I have an '04 CTS with a 3.6L engine. At about 90,000 miles the check engine light went on, even though nothing felt different. I took it in to the dealer and they did the following:
1 - replaced air filter
2 - "fuld decarb throttle body w/ moc cleaner"
3 - oil change

They said the engine light code indicated several problems, so I never did get a straight story as to what the code really was. On my receipt the code is P0341.

The car seemed to fun fine after that. Then I noticed the gas mileage had plummeted. Before I had been able to get nearly 400 miles on one tank. Now I am lucky to get 300 for well over 10 tanks now. It could be my imagination, but it FEELS like it's running rich. I took it back in and they charged me $50 to to tell me it looked fine.

Any ideas? I don't have much faith in the dealer anymore so any thoughts would be greatly appreciated. Thanks in advance.

 

P0341 code basically means that the powertrain control module (PCM) detected a problem with the camshaft position sensor (CPS).

none of this makes sense to me .. new codes please?



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I couldn't agree more. Which is why I am very frustrated. Attached is a scan of the work order along with description of the repairs performed. Every time I've put in a new air filter and cleaned out the fuel system, I've gotten BETTER gas mileage, not a 25% reduction in it.

The things I know for SURE are:

1 - My check engine light was on.
2 - When I picked my car up it was off.
3 - This is the bill I got.
4 - My gas mileage went south significantly with the first tank.
5 - I took it back and told the dealer this. They charged me $50 to take it on the highway and observe the instant mileage was around 25 MPG and declared that this meant nothing was wrong.

Thanks for taking ANY time at all on this ridiculous problem.