SUMMARY:
After installing euro headers, I am having serious problems with my primary O2s. I have gone through three sets in just 2 days. Initially, they work fine, voltage signals oscillating happily, no problems. But after a few miles they go dead: voltage signals drop to zero, or close to zero, in a couple of cases maybe one of them stays higher at 0.15-0.2V, but no oscillation. If I turn the engine off, the signals will slowly recover back up to 0.45V. I get SES light and codes 0x90 and 0x91 "dme: function, oxygen sensor control" bank 1 and bank 2. Post-cat O2s and EGT are deleted.
Every time I carefully check the wiring and clean the electrical connections, etc, but nothing fixes it until I just replace the sensor. Then with a fresh sensor in place, it goes back to acting properly. Error codes clear, voltage signal looks as it should. At this stage, once it's fixed, if I swap one of the previous O2 sensors in, it goes back to being broken. This seems to show that once the sensor fails, as described above, the failure is permanent and the sensor is now unusable. But a new O2 sensor always works, at least temporarily. But eventually, after some driving, both new sensors start to fail again (usually one at a time, but eventually both fail). Again, nothing I do fixes the problem until I put another sensor in.
I've now burned through three sets of O2 sensors (thankfully I had some new and used spares lying around, FCP bought).
The tune I'm running is Terra's CSL binary that I'm using on my MSS54HP, modified via Martyn's tool. I thought my problems were being cause by these modified tunes at first, but, my most recent set of O2 sensors died running on the tune I was using before I did the header install and tuned for cat deletion etc. I had been running this tune for a couple hundred miles already with no issues at all until I did the header install. My final attempt to validate that it's not the tune's fault is to start from scratch with Terra's binary, flash that, and then do all of the modifications with Martyn's tool in one shot. A more thorough description here. Have this "fresh" tune flashed on my DME now, but won't see if it works until I can get new O2s installed on Tuesday -- the sensors currently installed are dead.
I have no idea what's going on or how it's possible for O2 sensors to just flat out die like this. Any suggestions on what to try or look at would be very much appreciated. I've been on this for a couple of days now and I'm just bummed out and want to enjoy my car :[
The progression of my troubleshooting of this problem can be read below.
MOST RECENT UPDATE:
Went for a drive again this morning to check if everything was still working, and things still seemed to be great: both primary O2s behaving normally, and no codes for primary O2s. Then 10 minutes in I get the 'ol SES light. Check the scanner: code 0x91 (function, oxygen sensor control cyl 4-6). Check the sensor voltages and indeed, bank 2 has tanked to 0V, and bank 1 is still working perfectly. This is still on the pre-cat delete tune that I had been using before this entire debacle started.
So, this seems to also rule out the "cat delete" tune I made with Martyn's tool.
Quite frustrated now. The only thing that seems to be an apparent fact is that swapping in new primary O2 sensors always seems to fix the problem temporarily, but they eventually go bad again. And once they've "gone bad", they never seem to work properly ever again -- swapping in any of the sensors that have already gone bad doesn't improve anything, they stay bad. But swapping in a new sensor always fixes things at least temporarily.
So, now I need to ask: what running conditions could cause this to happen?
I'm going to re-make my entire tune from scratch, to see if I can rule out errors I've made in flashing/modifying binaries. But beyond that, any other suggestions?
SECOND MOST RECENT UPDATE: I think that I've determined that the problem is indeed the tune, which is causing the sensors to fail. Either I somehow royally screwed up my tune/program version combo (I definitely consider this the most likely scenario), or there's something subtly funky going on with Martyn's tool that caused this. Now I need help figuring out which.
Here's the reasoning that allowed me to isolate and fix the issue:
-The pattern I noticed: the O2 sensors were totally fine on the original catted tune, and then seemed to become irreversibly f***ed after running them on the cat-delete tune for more than 10 minutes.
(details of that pattern:
-I noticed that the pre-cat O2s that I installed with the headers were working perfectly upon install before I switched to the cat-delete tune I made with Martyn's tool. After switching to the cat-delete tune, they were working fine for the first 10 minutes or so, then everything tanked and both stopped being responsive. I switched back to the original catted tune I had before doing headers and the primary O2s still were unresponsive.
-Still on the original catted tune, while troubleshooting earlier today, I decided to swap in the extra used set of pre-cat O2s I had lying around. Like mentioned before, this seemed to completely fix the issue. The pre-cat O2s were now perfectly responsive. To sanity check, I swapped back in one of the other pre-cat O2s (that went dead after the initial header install and cat-delete tune), and it went back to being unresponsive. This made me believe that the O2 sensors themselves were the problem. Like I mentioned before, as I re-assembled the heat shields etc I kept running the car and checking that the O2s were still behaving, and they were: switching voltages as expected, and no codes.
-Once I was satisfied that I thought the problem was resolved by replacing the primary O2s with my spares, I then decided to re-flash the cat-delete tune that I made with Martyn's tool. After flashing, I turned the engine on, monitored O2 voltages, and they were behaving properly, and no error codes. So, this further reinforced my thinking that the problem was just the other O2 sensors, and not the tune. All makes sense.
-I start driving and a few minutes in, I get that SES and find that bank 2 O2 is now dead. I get very depressed, start trying to troubleshoot again, and during the process of troubleshooting, bank 1 sensor eventually dies too. Both sensors dead. Swapped the other sensors back in, they're still acting dead too)
-Hypothesis: the cat-delete tune is somehow killing O2s.
-Test used to validate hypothesis: Get a fresh set of O2 sensors, and run them for a while on the catted tune and see if they die. If they don't it would appear that it's the cat-delete tune that is causing the problem. I happened to have a pair of BNIB never used post-cat O2s. The bank 1 post-cat sensor actually happens to have an identical connector to the pre-cat bank 2 sensor, so I can use that one no problem. I go back to the catted tune. I swap in the sensor, and, what do you know, it fixes that bank -- voltage is switching again and no bank 2 codes. I want to swap in a fresh sensor for bank 1, but the bank 2 post-cat sensor's connector doesn't match the bank 1 pre-cat's. F*** it, I'm so close to figuring it out, so I get out an angle grinder and remove any trace of distinguishability from the new sensor's connector so I can plug it in to bank 1. Bam, voltage looks great, both banks are now behaving perfectly. No codes (other than for EGT and post-cat O2s, since I deleted those and this is the catted tune).
-Finally, I go and drive for an hour. To see if the pre-cat O2s continue to behave, or if they die like the last two sets did. They keep working. They still work now. Still on the catted tune.
Based on the above, my expectation is that if flash the cat-delete tune and go for a drive, both sensors will die, just like the last two sets did under the cat-delete tune. I don't want to try my luck until I can figure out what's going on here. I also expect that if I swap in any of the sensors from the last two sets that died, they will still be dead. This would pretty much absolutely confirm that the tune killed the sensors. I'm going to do that in the morning when the car's cool.
So, assuming that my reasoning holds up... why is the cat-delete tune killing the O2s? The tune is literally just the tune I was running before installing the euro headers (an 0401-PD31 partial), which was working perfectly at that point, loaded into Martyn's tool to have EGT disabled, secondary O2s deleted, and cat protection disabled.
Possibilities for my user error in dealing with the tunes:
1. The full binary I'm running is Terra's modified CSL program version, which I believe is based on the 0401-PD11 program version. However, the tune that I'm running (both the catted tune that worked fine and the cat-delete tune that is apparently not fine) is identified in Martyn's tool as 0401-PD31 program version. Not sure how this happened or if this "mismatch" matters and can cause the problems I'm experiencing.
2. The only modification I've made to my tune other than through Martyn's tool is modifying the cam offsets in TunerPro to match non-CSL spec cams. I did this using the 0401 XDF file found in the github stickied in the coding section. This is a pretty simple modification, and I believe that I did it correctly (which seems to be confirmed by the fact that I don't have any VANOS or timing related codes).
So... any ideas on how to figure out what's going on with the tunes?
Also, in the meantime: I'm running a tune that thinks I have post-cat O2s and an EGT sensor, but I don't. So it's throwing codes for those, and that's fine. Would this cause any other drivability issues? Would this keep the fuel system from getting into closed-loop or anything like that?
THIRD MOST RECENT UPDATE: I've been working on this since 4am and am quite defeated and confused. Overall, here is a summary in one place of the behavior I'm seeing and what I've tried:
-After installing euro headers and deleting post-cat O2s and EGT, I flash a new tune to accommodate the O2 delete and start seeing error codes 0x90 and 0x91, "function, oxygen-sensor control cyl 1-3" and "function, oxygen-sensor control cyl 4-6"
-When starting the car the O2 sensor voltages start at 0.45V and then within about a minute or less descend to 0V or quite close to it. Bank 1 plunges faster than bank 2. When I turn off the car but keep monitoring the O2 voltages, within a minute or two, the voltages slowly climb up from around 0 back to up 0.45V. So it doesn't exactly seem like the sensors are dead? Eventually after fiddling with connectors, I can get bank 2 to settle at a voltage of 0.15ish V but it isn't switching high/low like normal behavior. Bank 1 still sits between 0 and 0.05V. Codes persist for both banks. Code 0xD "signal, oxygen-sensor cyl 1-3" joins the party.
-I tried switching back to the old tune I had before doing the headers, and connect back the old postcat O2s and EGT sensor. Still have the same problem with the pre-cat O2s.
-I then dig back into the exhaust and decide to replace the bank 1 sensor with a used bank 1 pre-cat sensor I had lying around which I knew wasn't faulty. Also clean all connectors with QD electrical contact cleaner. I turn the car on, and lo and behold, it works! Bank 1's O2 sensor voltage is switching between 0.1V and 0.9 V as expected. Bank 2, which I didn't yet swap out, is still reading about 0.15V constant. Only the bank 2 code persists.
-I then swap out bank 2 sensor with another used bank 2 pre-cat sensor I had, and it fixes that bank as well. So, now, I have both banks showing the expected oscillating signal between 0.1V and 0.9V on both banks, and no codes! Success! At this point, I'm still reverted back to the tune that I was running when I had the stock catted headers, with the post-cat O2s and EGT plugged into the harness.
-I carefully put the heatshields back and get everything put back together. I check again that it's still fixed: both banks behave as expected, and no codes. So far so good. I then flash the tune that deletes the post-cat O2s and EGT. Turn the car on, run it for a few mintues, still fixed!
-I drive to the grocery store and get an SES light. Check the O2 signals: bank 1 is still working perfectly, bank 2 is reading a flat 0V. Two codes: "function, oxygen-sensor control cyl 4-6" and "signal, oxygen-sensor cyl 4-6".
-Carefully check everything, all the wires and connectors still look the way they should. Very puzzled why bank 2 decided to take a dump all of the sudden.
-Start fiddling with the connectors trying to gently re-orient them hoping for a miracle. Disconnect and re-connect a few times. Now bank 1's acting up again too, and its code is back. I am completely defeated.
It seems like it could have something to do with the connections to the harness, but it's not clear. Especially when replacing each sensor one by one made them work again, at least for a time, before going bad again, after running long enough on the cat-delete tune. Also when you turn the engine off but keep the ignition on you can see the voltages come back up. This makes me think that maybe something's coming out of the engine that's messing the sensors up? But what? Or it could be the harness connections for all I know.. but how do I troubleshoot that?
Desperate for more suggestions :/
ORIGINAL POST:
Installed euro headers today. Temporarily running catless (only for a few weeks with very little driving planned, already can't stand the sound and smell).
I used Martyn's ecuworx tool to disable EGT monitoring and delete the secondary O2s. When I drive the car, I get codes 90 and 91 saying "function - oxygen sensor control bank 1" and "function - oxygen sensor control bank 2". If I clear them they come right back.
What's wrong here? The secondary O2s and EGT sensor are completely removed/ungplugged. The primary O2s are plugged in and installed on the correct banks.
When I check fuel trims I get 0s for everything (including short term as I drive), so, it looks like the DME's not getting any O2 signals at all.
Any idea what's going wrong? Running Terra's CSL .bin modified with the ecuworx tool.
After installing euro headers, I am having serious problems with my primary O2s. I have gone through three sets in just 2 days. Initially, they work fine, voltage signals oscillating happily, no problems. But after a few miles they go dead: voltage signals drop to zero, or close to zero, in a couple of cases maybe one of them stays higher at 0.15-0.2V, but no oscillation. If I turn the engine off, the signals will slowly recover back up to 0.45V. I get SES light and codes 0x90 and 0x91 "dme: function, oxygen sensor control" bank 1 and bank 2. Post-cat O2s and EGT are deleted.
Every time I carefully check the wiring and clean the electrical connections, etc, but nothing fixes it until I just replace the sensor. Then with a fresh sensor in place, it goes back to acting properly. Error codes clear, voltage signal looks as it should. At this stage, once it's fixed, if I swap one of the previous O2 sensors in, it goes back to being broken. This seems to show that once the sensor fails, as described above, the failure is permanent and the sensor is now unusable. But a new O2 sensor always works, at least temporarily. But eventually, after some driving, both new sensors start to fail again (usually one at a time, but eventually both fail). Again, nothing I do fixes the problem until I put another sensor in.
I've now burned through three sets of O2 sensors (thankfully I had some new and used spares lying around, FCP bought).
The tune I'm running is Terra's CSL binary that I'm using on my MSS54HP, modified via Martyn's tool. I thought my problems were being cause by these modified tunes at first, but, my most recent set of O2 sensors died running on the tune I was using before I did the header install and tuned for cat deletion etc. I had been running this tune for a couple hundred miles already with no issues at all until I did the header install. My final attempt to validate that it's not the tune's fault is to start from scratch with Terra's binary, flash that, and then do all of the modifications with Martyn's tool in one shot. A more thorough description here. Have this "fresh" tune flashed on my DME now, but won't see if it works until I can get new O2s installed on Tuesday -- the sensors currently installed are dead.
I have no idea what's going on or how it's possible for O2 sensors to just flat out die like this. Any suggestions on what to try or look at would be very much appreciated. I've been on this for a couple of days now and I'm just bummed out and want to enjoy my car :[
The progression of my troubleshooting of this problem can be read below.
MOST RECENT UPDATE:
Went for a drive again this morning to check if everything was still working, and things still seemed to be great: both primary O2s behaving normally, and no codes for primary O2s. Then 10 minutes in I get the 'ol SES light. Check the scanner: code 0x91 (function, oxygen sensor control cyl 4-6). Check the sensor voltages and indeed, bank 2 has tanked to 0V, and bank 1 is still working perfectly. This is still on the pre-cat delete tune that I had been using before this entire debacle started.
So, this seems to also rule out the "cat delete" tune I made with Martyn's tool.
Quite frustrated now. The only thing that seems to be an apparent fact is that swapping in new primary O2 sensors always seems to fix the problem temporarily, but they eventually go bad again. And once they've "gone bad", they never seem to work properly ever again -- swapping in any of the sensors that have already gone bad doesn't improve anything, they stay bad. But swapping in a new sensor always fixes things at least temporarily.
So, now I need to ask: what running conditions could cause this to happen?
I'm going to re-make my entire tune from scratch, to see if I can rule out errors I've made in flashing/modifying binaries. But beyond that, any other suggestions?
SECOND MOST RECENT UPDATE: I think that I've determined that the problem is indeed the tune, which is causing the sensors to fail. Either I somehow royally screwed up my tune/program version combo (I definitely consider this the most likely scenario), or there's something subtly funky going on with Martyn's tool that caused this. Now I need help figuring out which.
Here's the reasoning that allowed me to isolate and fix the issue:
-The pattern I noticed: the O2 sensors were totally fine on the original catted tune, and then seemed to become irreversibly f***ed after running them on the cat-delete tune for more than 10 minutes.
(details of that pattern:
-I noticed that the pre-cat O2s that I installed with the headers were working perfectly upon install before I switched to the cat-delete tune I made with Martyn's tool. After switching to the cat-delete tune, they were working fine for the first 10 minutes or so, then everything tanked and both stopped being responsive. I switched back to the original catted tune I had before doing headers and the primary O2s still were unresponsive.
-Still on the original catted tune, while troubleshooting earlier today, I decided to swap in the extra used set of pre-cat O2s I had lying around. Like mentioned before, this seemed to completely fix the issue. The pre-cat O2s were now perfectly responsive. To sanity check, I swapped back in one of the other pre-cat O2s (that went dead after the initial header install and cat-delete tune), and it went back to being unresponsive. This made me believe that the O2 sensors themselves were the problem. Like I mentioned before, as I re-assembled the heat shields etc I kept running the car and checking that the O2s were still behaving, and they were: switching voltages as expected, and no codes.
-Once I was satisfied that I thought the problem was resolved by replacing the primary O2s with my spares, I then decided to re-flash the cat-delete tune that I made with Martyn's tool. After flashing, I turned the engine on, monitored O2 voltages, and they were behaving properly, and no error codes. So, this further reinforced my thinking that the problem was just the other O2 sensors, and not the tune. All makes sense.
-I start driving and a few minutes in, I get that SES and find that bank 2 O2 is now dead. I get very depressed, start trying to troubleshoot again, and during the process of troubleshooting, bank 1 sensor eventually dies too. Both sensors dead. Swapped the other sensors back in, they're still acting dead too)
-Hypothesis: the cat-delete tune is somehow killing O2s.
-Test used to validate hypothesis: Get a fresh set of O2 sensors, and run them for a while on the catted tune and see if they die. If they don't it would appear that it's the cat-delete tune that is causing the problem. I happened to have a pair of BNIB never used post-cat O2s. The bank 1 post-cat sensor actually happens to have an identical connector to the pre-cat bank 2 sensor, so I can use that one no problem. I go back to the catted tune. I swap in the sensor, and, what do you know, it fixes that bank -- voltage is switching again and no bank 2 codes. I want to swap in a fresh sensor for bank 1, but the bank 2 post-cat sensor's connector doesn't match the bank 1 pre-cat's. F*** it, I'm so close to figuring it out, so I get out an angle grinder and remove any trace of distinguishability from the new sensor's connector so I can plug it in to bank 1. Bam, voltage looks great, both banks are now behaving perfectly. No codes (other than for EGT and post-cat O2s, since I deleted those and this is the catted tune).
-Finally, I go and drive for an hour. To see if the pre-cat O2s continue to behave, or if they die like the last two sets did. They keep working. They still work now. Still on the catted tune.
Based on the above, my expectation is that if flash the cat-delete tune and go for a drive, both sensors will die, just like the last two sets did under the cat-delete tune. I don't want to try my luck until I can figure out what's going on here. I also expect that if I swap in any of the sensors from the last two sets that died, they will still be dead. This would pretty much absolutely confirm that the tune killed the sensors. I'm going to do that in the morning when the car's cool.
So, assuming that my reasoning holds up... why is the cat-delete tune killing the O2s? The tune is literally just the tune I was running before installing the euro headers (an 0401-PD31 partial), which was working perfectly at that point, loaded into Martyn's tool to have EGT disabled, secondary O2s deleted, and cat protection disabled.
Possibilities for my user error in dealing with the tunes:
1. The full binary I'm running is Terra's modified CSL program version, which I believe is based on the 0401-PD11 program version. However, the tune that I'm running (both the catted tune that worked fine and the cat-delete tune that is apparently not fine) is identified in Martyn's tool as 0401-PD31 program version. Not sure how this happened or if this "mismatch" matters and can cause the problems I'm experiencing.
2. The only modification I've made to my tune other than through Martyn's tool is modifying the cam offsets in TunerPro to match non-CSL spec cams. I did this using the 0401 XDF file found in the github stickied in the coding section. This is a pretty simple modification, and I believe that I did it correctly (which seems to be confirmed by the fact that I don't have any VANOS or timing related codes).
So... any ideas on how to figure out what's going on with the tunes?
Also, in the meantime: I'm running a tune that thinks I have post-cat O2s and an EGT sensor, but I don't. So it's throwing codes for those, and that's fine. Would this cause any other drivability issues? Would this keep the fuel system from getting into closed-loop or anything like that?
THIRD MOST RECENT UPDATE: I've been working on this since 4am and am quite defeated and confused. Overall, here is a summary in one place of the behavior I'm seeing and what I've tried:
-After installing euro headers and deleting post-cat O2s and EGT, I flash a new tune to accommodate the O2 delete and start seeing error codes 0x90 and 0x91, "function, oxygen-sensor control cyl 1-3" and "function, oxygen-sensor control cyl 4-6"
-When starting the car the O2 sensor voltages start at 0.45V and then within about a minute or less descend to 0V or quite close to it. Bank 1 plunges faster than bank 2. When I turn off the car but keep monitoring the O2 voltages, within a minute or two, the voltages slowly climb up from around 0 back to up 0.45V. So it doesn't exactly seem like the sensors are dead? Eventually after fiddling with connectors, I can get bank 2 to settle at a voltage of 0.15ish V but it isn't switching high/low like normal behavior. Bank 1 still sits between 0 and 0.05V. Codes persist for both banks. Code 0xD "signal, oxygen-sensor cyl 1-3" joins the party.
-I tried switching back to the old tune I had before doing the headers, and connect back the old postcat O2s and EGT sensor. Still have the same problem with the pre-cat O2s.
-I then dig back into the exhaust and decide to replace the bank 1 sensor with a used bank 1 pre-cat sensor I had lying around which I knew wasn't faulty. Also clean all connectors with QD electrical contact cleaner. I turn the car on, and lo and behold, it works! Bank 1's O2 sensor voltage is switching between 0.1V and 0.9 V as expected. Bank 2, which I didn't yet swap out, is still reading about 0.15V constant. Only the bank 2 code persists.
-I then swap out bank 2 sensor with another used bank 2 pre-cat sensor I had, and it fixes that bank as well. So, now, I have both banks showing the expected oscillating signal between 0.1V and 0.9V on both banks, and no codes! Success! At this point, I'm still reverted back to the tune that I was running when I had the stock catted headers, with the post-cat O2s and EGT plugged into the harness.
-I carefully put the heatshields back and get everything put back together. I check again that it's still fixed: both banks behave as expected, and no codes. So far so good. I then flash the tune that deletes the post-cat O2s and EGT. Turn the car on, run it for a few mintues, still fixed!
-I drive to the grocery store and get an SES light. Check the O2 signals: bank 1 is still working perfectly, bank 2 is reading a flat 0V. Two codes: "function, oxygen-sensor control cyl 4-6" and "signal, oxygen-sensor cyl 4-6".
-Carefully check everything, all the wires and connectors still look the way they should. Very puzzled why bank 2 decided to take a dump all of the sudden.
-Start fiddling with the connectors trying to gently re-orient them hoping for a miracle. Disconnect and re-connect a few times. Now bank 1's acting up again too, and its code is back. I am completely defeated.
It seems like it could have something to do with the connections to the harness, but it's not clear. Especially when replacing each sensor one by one made them work again, at least for a time, before going bad again, after running long enough on the cat-delete tune. Also when you turn the engine off but keep the ignition on you can see the voltages come back up. This makes me think that maybe something's coming out of the engine that's messing the sensors up? But what? Or it could be the harness connections for all I know.. but how do I troubleshoot that?
Desperate for more suggestions :/
ORIGINAL POST:
Installed euro headers today. Temporarily running catless (only for a few weeks with very little driving planned, already can't stand the sound and smell).
I used Martyn's ecuworx tool to disable EGT monitoring and delete the secondary O2s. When I drive the car, I get codes 90 and 91 saying "function - oxygen sensor control bank 1" and "function - oxygen sensor control bank 2". If I clear them they come right back.
What's wrong here? The secondary O2s and EGT sensor are completely removed/ungplugged. The primary O2s are plugged in and installed on the correct banks.
When I check fuel trims I get 0s for everything (including short term as I drive), so, it looks like the DME's not getting any O2 signals at all.
Any idea what's going wrong? Running Terra's CSL .bin modified with the ecuworx tool.
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