Chevy Cobalt Misfire At Idle And Lean Codes

I have a check engine light on my 2007 Chevrolet Cobalt 2.4l engine. Had the codes scanned and they found P0171 and P0300. Lean exhaust condition and misfires. What can cause this problem and how do i fix it myself. I dont want to go to a shop since they are so expensive these days and I have a small budget. 87,000 miles.

See picture below. This problem should under warranty. It is common to 2006 and 2008 models also. A common cause for this is the fuel injectors are slightly restricted. The dealer will perform a fuel injector balance test and do a cleaning procedure. If the injectors do not show improved flow, they will be replaced.

There is also a reprogram for the Powertrain Control Module (PCM). I suggest getting in as soon as you can. With the check engine light on, you will not be able to pass state emissions test, and can cause more problems with the way the car runs.

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If none of thee things fix the car, then you have a problem in the cylinder head. The valves and seats may be full or carbon and are pitted. This will give a misfire and lean AT IDLE ONLY. The cylinder head would need to come off, the valves cleaned or replaced, and the valve seats repaired. If the head cannot be repaired, it will need to be replaced.

Chevy Cobalt cylinder head and valves damaged causing rough idle and missfire codes.

2007 chevy cobalt 2.2L Ecotch 4 cylnder, Engine code engine poor reduced performance code P2176. Do i need to replace them and where are they on my car.

Not sure what you mean by "replace them". Most likely your problem is a bad throttle body.

2002 Chevy Cobalt. I installed a new a/c compressor and serpentine belt. After changing out a/c compressor, the clutch would not engage. We checked the fuse panel and found the fuse blown. Put in one of the spares and it blew as well. We put in a spare 20w fuse and the engine stopped running. The fuse panel is getting power to the fuses on the outside edges of the panel, but not to the fuses in the center of the panel. When we hot wired the ign fuse, the car started and ran fine. What would be causing this. Thanks.

If the A/C fuse keeps blowing, then you put a bigger one in, you may have caused the original short to get worse and blow something else.

I think there is a fuse labeled "Powertrain" in the under hood box. If that is OK, then check all fuses. If they are all good, then you need to look for some melted wires or possibly the fuse box itself is bad.

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