OFT and Catless Header Install - o2 circuit CEL? (0031 & 0037)

[quiet-k]

Would greatly appreciate anyone's thoughts on this...is this even tune related?

I had been running the stage 1 tune with an axle-back and hadn't had any problems. I recently upgraded to a JDL UEL header (catless) and overpipe (both with fresh gaskets) along with a K&N filter in the stock air box. Given those changes, I decided to move up to the stage 2 tune. Once I did, I started getting a CEL (0031 and 0037) for the o2 sensor circuit - not the standard o2 sensor catless header CEL.

I thought I might have damaged the circuit during install, but after thorough testing and even swapping in new o2 sensors and testing them, I still can't get the lights to clear. If I clear the CEL while the car is running, the idle rpms increase by about 500 for a few secs and it idles a bit rough and then the lights come right back on.

Is this something anyone has encountered before? My guess is that there's something going on with the tune and the o2 sensors, but I'm not really sure what...

[steve99]

Originally Posted by quiet-k

Would greatly appreciate anyone's thoughts on this...is this even tune related?

I had been running the stage 1 tune with an axle-back and hadn't had any problems. I recently upgraded to a JDL UEL header (catless) and overpipe (both with fresh gaskets) along with a K&N filter in the stock air box. Given those changes, I decided to move up to the stage 2 tune. Once I did, I started getting a CEL (0031 and 0037) for the o2 sensor circuit - not the standard o2 sensor catless header CEL.

I thought I might have damaged the circuit during install, but after thorough testing and even swapping in new o2 sensors and testing them, I still can't get the lights to clear. If I clear the CEL while the car is running, the idle rpms increase by about 500 for a few secs and it idles a bit rough and then the lights come right back on.

Is this something anyone has encountered before? My guess is that there's something going on with the tune and the o2 sensors, but I'm not really sure what...

Those codes are for 02 sensor heater circuit problems.
Either your 02 sensors or wiring is damaged or you have sensors plugged in wrong sockets.
Should be Black plug to black socket, grey plug to grey socket

Last guy that had tose codes shop forgot to plug sensors back in.

Its not an issue with header leaks or install or the tune its electical problem or 02 sensor issue, if your rearly unlucky you may have damaged ecu if wiring is shorted but unlikely.

[Shiv@Openflash]

This leads me to a question: Does steve99 ever sleep?



Great help as always!

[steve99]

Originally Posted by Shiv@Openflash

This leads me to a question: Does steve99 ever sleep?



Great help as always!

yes but work weird hours

[quiet-k]

Originally Posted by steve99

Those codes are for 02 sensor heater circuit problems.
Either your 02 sensors or wiring is damaged or you have sensors plugged in wrong sockets.
Should be Black plug to black socket, grey plug to grey socket

Last guy that had tose codes shop forgot to plug sensors back in.

Its not an issue with header leaks or install or the tune its electical problem or 02 sensor issue, if your rearly unlucky you may have damaged ecu if wiring is shorted but unlikely.

Thanks for the reply Steve!

Sensors are definitely plugged in correctly. I have a set of brand new replacement sensors that still throw the same codes too.

Certainly hope it's not damaged ecu...

[Shiv@Openflash]

Originally Posted by quiet-k

Thanks for the reply Steve!

Sensors are definitely plugged in correctly. I have a set of brand new replacement sensors that still throw the same codes too.

Certainly hope it's not damaged ecu...

It's almost certainly not a damaged ECU.

[JB86'd]

Did you undo your battery when installing? Wonder if it could be a blown fuse somewhere..my best guess considering you've tried everything.

[quiet-k]

Originally Posted by JB86'd

Did you undo your battery when installing? Wonder if it could be a blown fuse somewhere..my best guess considering you've tried everything.

Yup. Definitely undid the battery. Checked the fuses too.

[JB86'd]

Have you tried clearing the CEL while the car is not running?

[steve99]

Originally Posted by quiet-k

Yup. Definitely undid the battery. Checked the fuses too.

http://forums.nasioc.com/forums/show....php?t=2664042



dont have brz\86 wiring handy but their will likely be a fuse hidden some where their are a cople of fuse box locations , something like a\f heater fuse as above.

[quiet-k]

Originally Posted by steve99

http://forums.nasioc.com/forums/show....php?t=2664042



dont have brz\86 wiring handy but their will likely be a fuse hidden some where their are a cople of fuse box locations , something like a\f heater fuse as above.

Thanks - I'll take a peek at that guy tonight!

Also, I did clear the codes while car wasn't running. They cleared with the new o2 sensors, but immediately came back on when I started the car.

[knandez17]

Hey man I had this same exact issue, Steve is probably referring to me lol. I tried reflashing, clearing codes, everything to no avail. Turns out the shop screwed in the o2 sensors in the wrong way.

Steve, as an aside, I'm still getting awful mpg post-tune uel, header, dp/op install. It's been a good 2-3k since I flashed. Talking dropping from 25-26 average to 21. No change in driving either. Why could this be? Don't want to take it to the dealer and they start fiddling with the uel..

[quiet-k]

Originally Posted by knandez17

Hey man I had this same exact issue, Steve is probably referring to me lol. I tried reflashing, clearing codes, everything to no avail. Turns out the shop screwed in the o2 sensors in the wrong way.

Steve, as an aside, I'm still getting awful mpg post-tune uel, header, dp/op install. It's been a good 2-3k since I flashed. Talking dropping from 25-26 average to 21. No change in driving either. Why could this be? Don't want to take it to the dealer and they start fiddling with the uel..

Screwed them in the wrong way? Like cross-threaded? Or the wrong one in front/back?

Thanks for the input!

[knandez17]

Turned out to be the wrong one in the front.