06 2.2 showed p0302. Changed all plugs, #2 injector, boots, coil and module. Light would go out briefly after each repair then return. Now shows p0300. Has 23,000 miles since new. Checked engine grounds and have looked for vacuum lines but don't really see any. Also mil comes on usually under acceleration and turning left. Three times it stalled at traffic light when shifted into neutral. New gas cap arriving tomorrow from Amazon. Ac delco replacement but don't think it will cure anything as car just went through inspection and gas caps are the last thing they check here in New Jersey. When light comes on it will go out after a couple of starts and drives but then return again after a few miles. Car runs good but doesn't feel quite right when holding hand near tailpipe while idling. Does seem to have slight miss. Thanks.

 

I seem to recall a problem with crap in the fuel rail causing misfires on turns.

Is it always P0300?

 

P0300 suggestions
http://www.obd-codes.com/p0300
P0302 suggestions
http://www.obd-codes.com/p0302

Double check what you have done and what you might not have .

Perhaps a battery lobotomy is in order, disconnect the negative cable at the battery for a full 30 minutes to reset the ECM.

I don't fully belief it will cure the issue but as you did replace the #2 fuel injector, maybe the system doesn't know it.

 

I'll try battery suggestion tomorrow and post result. At this stage it certainly can't hurt anything. Thank you for the suggestion. I know these new cars are touchy and can be very cantankerous at times.

 

They don't like to sing Thank's for the Memory

 

Donbrew - good memory on the fuel rail issue there lad :)

https://www.chevyhhr.net/forums/prob...misfire-19566/
Post 4: https://www.chevyhhr.net/forums/prob...balance-43947/

Post 26: https://www.chevyhhr.net/forums/prob...e-46326/page3/

 

Pulled battery cable and after 3 hours reconnected. Showed p0303 and after about 15 mins switched to p0302. I think this car is demented. Scanned each cylinder. Number 3 showed misfire then didn't. Number 2 showed none then did. Also replaced gas cap today. Have a friend who works in parts at dealership. He has been trying to help but today suggested to bring it in and let them take a look at it. I'm afraid this could be a software problem as I have replaced about everything within reason and nothing's changed.

 

2006, you replaced the coil pack?
What about the spark plugs, are they AC Delco 41-103's?

 

How could the computer get fouled up?

Why did you change the gas cap? You didn't mention a vacuum/evap code.

Why not do some troubleshooting before throwing money at it? P0300 means "random misfire", so you should not be surprised that the cylinders change.

 

Here's another one