2c31 Code

[danmcg]

So today I was cruising home on the highway and about 10 mins from my house the SES light comes on. Got home and plugged in the handy dandy laptop to my JB4 and this is the code that I pulled:

2C31 Lambda probe in front of catalytic converter, trimming control

I didn't notice the car behaving weird or anything although I didn't goose it since obviously there was something that triggered the light. I cleared the code out and shut the car off in the driveway.

From Googleing around a bit it seems to be an o2 sensor perhaps? The only thing I have done to the car is install the JB4 about 5 days ago. I was running map 1 until yesterday when I moved it to map 5. I put about 5 gallons of gas in it from a crappy gas station cause I was super low and towards the middle of the state where you take what you can get. I'm hoping that this gas wasn't SO bad that it fouled up the o2 sensor (if that indeed is what is going on here). Is that even something to worry about anymore?

[shodanusmc]

Maybe it is nothing, but it could be a lot if you have to take the car in to BMW. Naturally remove the JB, clear everything, and hope they do not dig. If the car is running fine outside of the code, I would not think it is the gas, but just a guess.

[BMW86]

Any updates on this? My car throws 2C31. Replaced front o2 sensors but still get the codes.

[danmcg]

This ended up being because I had the DP fix still installed. Once I removed it the codes went away. Haven't had an issue since.

Thanks Terry!

[BMW86]

Originally Posted by danmcg

This ended up being because I had the DP fix still installed. Once I removed it the codes went away. Haven't had an issue since.

Thanks Terry!

Thanks for the reply mate. How long after removing the DP fix did it go away? Did you have any symptoms or just the code itself? My car hesitates under WOT and eventually limps.

[danmcg]

I cleared the codes and removed the DP fix and all was well immediately.

[J-Sud]

why would the DP fix throw a code? Are you not using catless DPs?

[danmcg]

Nope. It was a used JB4 that I installed that was running a car that had FBO and meth. I just didn't realize what the DP fix was because I thought it was something that was built in is all. My car is just the tune.

[J-Sud]

cool...makes more sense now