Help with codes 2C31 and 2C2C

[jbash87]

Originally Posted by SlowX6M

So the weather has been great in NY, and I haven't touched my car since Saturday, have been riding one of my motorcycles, and my wife has been driving my car instead of hers because it's more suitable in the winter.

Meanwhile, I had ordered the lower CCV hoses and two pre-cat O2 sensors. The order arrived early this afternoon, and soon as my wife got home from her errands I went out to change out the O2 sensors. I first went to start the car to erase the code, and lo and behold, the CEL was off.

Connected to Bimmerlink, read code memory, it shows 2C21 and 2C2C but says the fault has not yet occurred. I hope that maybe after I replaced the spark plugs and upper CCV tubes, it took the ECU a while to adjust the long term trim, and now the CEL is off for good.

I still replaced both O2 sensors, just because - after 109k miles, might as well. My wife is driving my car to VA tomorrow and back next week, hoping the CEL stays off.

P.S. When I took out and swapped the old O2 sensors from side to side, I cleaned them up with sensor cleaner. When I took them out today, they were covered with black soot, just like when I first took them out. I assume this is normal and to be expected.

Fingers crossed!

And yes they will be covered. Especially if your car still has cold start enabled.

[SlowX6M]

Originally Posted by jbash87

Fingers crossed!

And yes they will be covered. Especially if your car still has cold start enabled.

Wife is back early, over 500 miles in 2 days, the CEL never came back, so it's probably off for good. Did you also get these 2 codes after spark plug/ccv hoses change, or was it random?

I will still attempt to replace the two lower hoses since I already have them, but when the weather is warm.

Also, what do you mean by cold start enabled?

[jbash87]

Originally Posted by SlowX6M

Also, what do you mean by cold start enabled?

Not sure if you have an aftermarket tune or not, but many people who go cat-less and get aftermarket tunes will disable cold start because it is no longer needed.

[SlowX6M]

Originally Posted by jbash87

Not sure if you have an aftermarket tune or not, but many people who go cat-less and get aftermarket tunes will disable cold start because it is no longer needed.

Totally forgot about a tune, I did install a Dinan tune on it a few years back, that claims like 500 horse power, or something to that extent. Didn't feel any difference in driving, but the exhaust system is all stock.

[SlowX6M]

The CEL was off for a few weeks, but now started coming back. I am thinking leaking injector(s)? They were replaced almost 100k miles ago.

[jbash87]

Originally Posted by SlowX6M

The CEL was off for a few weeks, but now started coming back. I am thinking leaking injector(s)? They were replaced almost 100k miles ago.

There is a fuel system test you can run in ISTA on other models. Perhaps the S63 has one?

[SlowX6M]

Mine is N63, 5.0 X5. I have to play with ISTA some day.