P0420 & P0430 codes at same time with new supersprint cats

[mcfreid]

Installed supersprint headers and cats last winter. Replaced all o2 sensors at the same time. I've put on about 1k miles on the car since then. Today the service engine light came on with codes P0420 and P0430 at the same time.

Could use some help on where to look first. What are your thoughts?

FYI: also recently replaced the engine air filter, if that matters at all.

[repoman89]

Just how it is. It's always low load highway cruising that throws the light for me. I've tried turning down the secondary O2 thresholds multiple times but got tired of the codes continuing to appear and just turned them off. I would recommend you do the same.

[sapote]

Installed supersprint headers and cats last winter. Replaced all o2 sensors at the same time. I've put on about 1k miles on the car since then. Today the service engine light came on with codes P0420 and P0430 at the same time..

Are the car stock or aftermarket units? The codes say the cats don't do a good job to clean the pollutant -- the DME detects abnormal post cat sensor signals.
Can you collect the data in the log file, using OBDFusion with the following parameters at warm engine idling: rpm, MAF, coolant temp, precat O2 and post cat O2, FTFT and STFT for both banks.
I use VeePeak dongle for the OBD port, and OBDFusion app on iphone.

[mcfreid]

I'll check out VeePeak and OBDFusion and let you know!

The cats are HJS units supplied in Supersprint's section 1. Surprised the codes would have come in at exactly the same time for both cats if one of the cats was doing a poor job.

[PSUEng]

Subscribing to this one--I'm getting these exact same codes on my stock cats, hence the motivation to go with this SS system. Hoping I didn't waste the $$ on the cats when the post O2s ultimately need turned off anyway.

EDIT: Came across an interesting thread on another forum where a Z4M owner had issued with his SS system due to EGT placement--more so power delivery and the ECU activating cat protection. Not sure if that's related here to this issue, but does raise the question: on our cars, EGT should be relocated to Section 1, or used in the header? SS apparently provides locations for both.

[mcfreid]

sapote Finally got a chance to take the logs. Screenshots below and CSV logs here https://docs.google.com/spreadsheets...it?usp=sharing.

Not sure how to read the data or what to take away from this. Please let me know if you see anything unexpected.

[maupineda]

It seems as if the CATs are doing nothing, the voltage reading should be steady, not cycling same as pre cat sensors.

o2s2 b1 and o2s2 b2 should be ~0.6-0.7 volts and look more like “flat” lines. Did they forget to coat the cats? Seems like you have empty substartes.

make sure car is warmed up before logging the data.

[mcfreid]

Car was warmed up, but only via idling for 10-15 minutes. Wasn't driven. Will drive around and take more logs that way.

[mcfreid]

Screenshots below are during warm idle after a 1-hour drive.

[maupineda]

Your cats are faulty, assuming you O2 sensors are good, but based on you data, they are, otherwise you would see a flat line. Basically the rears are seeing the same as the fronts. If you have warranty, use it.

[mcfreid]

Damn, just to make sure though - the y-axis on those charts is a bit misleading. From the O2S1, the y-axis is from 0 to 1 whereas for the O2S2 the y-axis is 0.7 to 0.8 - comparitvely it's certainly more of a flat line than the O2S1 if you plot them on the same axis. Here's screenshots when plotted together.

[maupineda]

Oh! What a dumb I am!!! I did not look at the scale in detail. They seem to be fine, what i understand is that 0.6-0.7 is correct, yours fluctuate to up to 0.8, perhaps is just that is outside the spec.

[mcfreid]

Hmm, anyone else with supersprint/HJS cats know whether the 0.7 to 0.8 voltage numbers for the post-cat O2 sensors are normal? If so, did you have to change the coding in the ECU to accept those voltage numbers, or perhaps a different cat warm up sequence?

[akamin68]

Simple two step fix. 1) code the post cat 02 sensors out. 2) drive.


Sent from my BTV-W09 using Tapatalk

[mcfreid]

Would rather not code them out in case of smog checks.