2007 running rich on bank 2

[B-train]

Have you ever replaced the MAP sensor? If so, I've sewn sensors for the wrong application/generic give that sort of issue with traction control light coming on and off

 

[03GMCYukonXL]

So update. This issue went away with warmer weather. I thought maybe the problem fixed itself lol. However, now with the cooling weather, the issue has returned. Now the real funny thing is, it seems to do it the worst between 50 and 70 degrees. When it's real cold, it isn't as bad, but still present. In the heat it's never present.

It's only at idle, or once it's been under load at speed and then I let it coast. As in climbing a hill and then coasting down. Once I give it throttle and it's under load again, the light goes out. So it makes sense what was previously mentioned about a leaking gasket causing a lean condition and the compensation from the ecu puts it in a rich condition once the rpms are down. I actually have a set of metal intake gaskets that came with my Texas speed DoD delete kit. I'll swap these out in the coming weeks and see if that helps

 

[Discodisco]

You really need to get fuel trims before you can do anything, since it’s only on one bank it’s somewhat isolates what you need to look at but it could be anything from a vacuum leak to an injector to a o2 sensor.

 

[Fless]

You really need to get fuel trims before you can do anything, since it’s only on one bank it’s somewhat isolates what you need to look at but it could be anything from a vacuum leak to an injector to a o2 sensor.

Add to that an exhaust leak on that side as @j91z28d1 posted.

 

[Discodisco]

Yeah an exhaust manifold or gasket leak could certainly introduce post combustion air into the exhaust before the sensor making it think it’s running lean and richening it up.

 

[03GMCYukonXL]

Funny thing is, I have a popped exhaust manifold bolt on bank one. Bank 2 bolts are fine. If it was a bad 02, wouldn't it throw a code? The service stabilitrak light literally only comes on at idle or after I've been driving under load and then let it coast.

 

[Discodisco]

Funny thing is, I have a popped exhaust manifold bolt on bank one. Bank 2 bolts are fine. If it was a bad 02, wouldn't it throw a code? The service stabilitrak light literally only comes on at idle or after I've been driving under load and then let it coast.

you got an oil pressure issue my friend, im willing to bet that you also have a p0111 stored for the variable cam timing. when your sitting at idle oil pressure is probably low and when you come off a heavy load to no throttle it dips too.

To further answer your question though, its hard to say without fuel trims, the PCM is designed to set a fault once a certain value is exceeded in a binary matter, simple yes or no, the fuel trims though can vary anywhere from -9% to + 9% (roughly) without setting a fault.