good day. I have a 2007 Monte Carlo LT...I have a problem with my p0140 code (sensor). the dealer repair the problem, but the 'check engine' light is still on...I heard that there is a fuse somewhere. and if anyone knows where it is I'll be greatful, I hope you can help me.

 

Id talk to the dealer first. Should have some kind of accountability/ warranty on the work they did, especially if they didn't do something right and caused the fuse to blow.

There is an O2 fuse (under hood on 6th gens, not sure about yours), but if it is blown, you really should spend some effort figuring out why.

 

I have 114K right now. I was outside under the hood and I couldn't find anything.

 

I didn't mean the original warranty, I mean a warranty on the service work done. You said the dealer repaired it, but you got a check engine light. They should have some kind of accountability if they did the job incorrectly (just speculating on cause of course).

At a minimum, I'd want them to be aware that I paid a bunch of money for them to fix somethign that didn't actually solve the problem. They need to be aware that their tech screwed that one up.

Just flipped through the owners manual and I see what you mean - layout is different from the 6th gen. Clearly they still use power, it just must be rolled into a different fuse name.

I wonder if that could be Emissions 1 / 2?

Another option if you think its a fuse - just continuity check all fuses from the top that have anything to do with the engine.

 

Yes...I'm going to check it out tomorrow. I've been back to the dealer 3 times in 3 months.

 

I have changed all the fuses in the engine area the past weekend ...and no luck. my sensors are new. I'm not sure what to do.

 

Oh yikes - I would've just tested continuity across the pins. Wouldve been a lot easier.

If the dealer has given up, (and assuming you don't have electrical circuit troubleshooting experience), it sounds like you need to find another shop that can properly diagnose electrical faults.

There's really not a whole lot to this code - the sensor, the wiring, and the pcm itself (or potentially the grounds / feed power to the pcm). But someone is going to have to brute force through the steps with a multimeter to figure out where the breakdown is.