Engine Cycle Suggestions - Emissions Rejected

[mrgizmo04]

You're right its not a simple battery disconnect but it IS simply a battery disconnect for an extended period of time (several weeks). I've experienced this more than 3 times on E46 and E53 chassis. Happy to proven wrong if there's a credible source referenced.

I disconnected for a day to test the theory that everyone keeps saying do not disconnect the battery (which you should do to work on electrical things, swapping sensors, coils, etc).

So I have that as a data point.

I don't know if leaving the battery off for weeks would drain the memory (but sounds like it might).

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[jbfrancis3]

You're right its not a simple battery disconnect but it IS simply a battery disconnect for an extended period of time (several weeks). I've experienced this more than 3 times on E46 and E53 chassis. Happy to proven wrong if there's a credible source referenced.

[mrgizmo04]

Unlike popular belief, disconnecting the battery does not reset the monitors. Clearing codes, swapping sensors, clearing adaptations, getting and having stored faults, does. You can plug things into obd port and run scans, that's how you check that the monitors are set so you are not surprised at the testing center.

You need to also understand what happens during the "drive cycle". Like if your SAP or EVAP are not set, you do not need to drive the car, because those specific monitors are only tested and set during a cold start. If your o2 are not set, you don't need to idle the car from cold start for 5 minutes, because o2 monitors are only tested and set during a constant speed drive on the highway. You CAN stop at stop signs and red light on the way to an open road/highway (again unlike popular belief). You can accelerate/decelerate, etc, just the o2 test starts once you are at constant speed. RPM and MPH limits are true. The "run all red lights" on the way to highway are not.

I think people bend over backwards a bit too much following those strict rules when they dont need to. Isolate what you need to set, understand what condition is required to be met for it to set, and follow it.

The 20min cruise around thing...depends. If your hardware is in good condition (fresh sensors etc), it can set a lot quicker. I had my obd2 plugged in during the drive, running a scan via obd fusion app, and my o2 monitors set within 3 mins, so I got off the highway, no need to keep driving for 20mins.

I just did all this for my CA smog test, I recorded videos to post on youtube explaining things, but I have no time to edit at the moment.

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[Estoril]

I used this. It worked. Done and drove right to the emissions stations and success. Choose the right "not crowded" road that you don't have to brake, speed up to merge or otherwise fall outside the limits.


"The drive cycle consists of four tests. Each test can be done independent of the other tests. It does not matter what order you complete the tests in. Only one of the tests requires a cold start, the other three do not.

To solve your problem, you need to complete the third test shown in the graphic. You do this through the following process:

1) Fix all transmission and engine light faults before emissions testing and completing drive cycle tests. Before you perform the test, I strongly suggest you download the app called "Torque" on your phone and turn on the emissions control screen. This screen lets you know what tests you have completed in real time. In this case, you'll be looking at the Catalytic Converter test. You'll need a $10 blu-tooth OBD connector to connect the car to the phone. This step is optional, but you'll see why it is helpful in later steps.

2) Start your car and go directly to the freeway. DO NOT exceed 3000 rpm, DO NOT make sudden or large accelerations/decelerations, and DO NOT exceed 60 mph on your way to the freeway. Doing any of these will stop the test immediately and the test won't restart unless you restart your car. For these reasons, you'll want to get onto the freeway at night, preferably after midnight when traffic is the lowest. For me personally, I absolutely HAD to get my emissions test completed within a narrow time frame. To ensure I was successful, I did this test at 3AM when there is ZERO traffic.

3) Once on the freeway, SLOWLY accelerate to 55 mph and set the cruise control at 55mph. Just chill in the slow lane for 20 minutes (just to be conservative) and let the computer run its tests. As long as you stay in the slow lane, you're golden. If someone tailgates you, just stay where you are. You're in the slowest lane, they can go around.

4) Once 20 minutes has passed, get off the freeway. Open the Torque app and confirm the drive test is complete.


5) DO NOT do any work on your car until you get the emissions test done. DO NOT disconnect the battery. DO NOT run any diagnostic or performance software plugged in via the OBD port. DO NOT make software modifications. DO NOT clear any codes from the car at all. Wait until you've completed emissions testing to do any of these because the emissions test results get wiped from the ECU when you do them. If you wipe the results, you gotta perform the test again.

The test is easier than you think and works like a charm. That said, BMW engineers are retarded for requiring the test to be performed between 40 and 60 mph for 15 minutes. Essentially all American freeways are 65mph, so its hard to do the test during routine traffic without pissing off other drivers or getting stopped in rush hour. Stopping ceases the test. Two-lane undivided highways pose their own problems for the tests because some turns may force you to slow down beyond the bounds of the test (slower than 40mph) and hitting a stop sign ensures you have to start over. Secondly, for those of us with M3's, we almost always exceed 3000 rpm in first gear (and often in 2nd and 3rd too), we like going faster than 60mph, and we like sudden accelerations. My last point is EXACTLY why so many of us end of with cars not ready for emissions after we've worked on our car and cleared codes."

[jbfrancis3]

Yes its simply the battery being disconnected that caused it. I understand it to be approx 100 miles like you mention

[turbosig]

Anyone know the exact procedure for the Engine Cycle to get the Cat and O2 sensors in the "passed" or "ready" during an emissions test? 2004 M3, the car is a garage queen and during COVID I had the GM5 out and sent to Scott for repair/diag of failing actuator or door locks. Anyways, the car was sitting without battery for a week or two while waiting to get it back and reinstalled - which I am assuming is what reset the cycling.

I barely drive the car and today decided to get it inspected as it was overdue. Lo and behold everything else passed except the "Cat" and the "O2 sensor". I am in NJ and the car came with me from CA which has even stricter emissions test than NJ. I have never had an issue before, and the NJ MVC (DMV) said that I just need the engine to go through a cycle or two. They gave me some pamphlet about how to do it, but I figure I ask the experts here. From what I've read online some people have just driven the car 100 miles while others have done the lengthy process of cold start, than 20-30MPH and then 50-50 under 3K RPM, etc...

Is there any one way to get the engine to cycle? I even came home and plugged my OBDII reader in and it said the same thing Cat was "INC" and O2 was "INC" too.

Thanks in advance!