CEL still on even with O2 bung
 

Got a TurboXS HFC on my 14 EVO mr. Installed the L bung and I added the spark plug foulers so my rear o2 sensor would have a good distance but still my CEL is still on. Any suggestions? Thank you :)

Did you reset the code? It can take over 50 miles for it to reset on its own. If you have a code reader you can clear it by that, or just unplug the battery for a few minutes.

I did unplug the battery and the CEL went off. After driving it by 50+ miles it went back on again :(

Im thinking of puttibg in some steel wool on the bung

Sometimes you just gotta mess around with the amount of spacers. Like on my car I just have two spark plug non fowlers on there, and that did the job. Some people only need 1. Try taking the L bung off, and just use the non fowlers.

What code are you getting? I had this issue for around a year and just finally figured it out after putting it off for a long time. If you are getting a P0140 you need to get rid of the spacers and just put the sensor in normally. That's what seems to be working for me.

Im getting the P1037 code. Heated sensors.

Sounds like the sensor is too far out from the exhaust flow..

here is what I saw for P1037

This, is interpreted by the ECM as a low voltage condition and sets the MIL. Bank 1 Sensor 2 is located to the rear of the catalytic converter and should produce an output signal relative to oxygen storage capacity of the catalytic converter. This rear (sensor 2) sensor is less active than the signal produced by the front sensor. However, if the ECM senses the sensor is inactive, this code will set.

Read more at: http://www.obd-codes.com/p0137
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I see. Im gonna try to remove the L bung today.

It's a hit or miss the evo.

It went away again, then came back after 50 miles *sigh* guess I'll have to live with it, can you disable the rear o2 sensor in cobb AP? I was reading on disabling the rear o2 sensor through evoscan and ecuflash but I have no idea how to use those. :(

yes you can. I believe it is in the toggles on the access tuner software. just modify the map you are using to turn off the CEL and then load the map onto the ecu

Watch your A/F ratio if you disable the rear O2. Messed up my idle/cruise A/F ratio badly. Went rich as hell, basically pegged the gauge at 10:1.

The rear o2 wouldn't cause that. It's only purpose is to make sure the catalytic converter is doing it's job. The front o2 controls AFR in closed loop

ive been having the problem for about a year now. ive tried steel wool, spacers. im starting to thing the wiring or the o2s gone bad.