Two days ago my 2.2 was misfiring horribly. Found out my ignition coils for 2,3 went out. Replaced them. Drove fine the next day. Today I just started her and its doing the same thing. Anyone know what the hell is going on? I called my friend whose a master mechanic at the chevy dealer but hes not gonna be over for a few hours.

 

What year cobalt do you have. If it's 05-06 then check spark plugs and Iginition Control Module. If it's later then I'd check your spark plugs

 

if your a 05-06 check ur ICM, if your a newer year than time to check them coil individualy, go get urself a screwdriver, stick it in the coil and try and crank it, do this to all of them and see that they all get sark, trust me, you will know which ones are working, i know i ran on 2 cylinders when the ICM blew, and 2 days later the cat followed it

 

i had the same problem but mines an 07 , but same problem went straight to the dealer they told me spark plugs, but did not think so, went to another they told me a miss fire and would be ok to drive. But my gut said no try again, turns out my head had fallin apart and the was only three valves still conected.

 

lol nice

 

yeah but it sounded like a v8 drag car threw my intake

 

Okay so we changed the ICM again. It ran fine for a day. Now its doing the same thing. No spark 2,3. We checked wiring and ECU. Any suggestions? Changing the coils doesn't help but changing the ICM does. But only for a day.

 

try some new gas the stuff you put in could of been old.. had a massive missfire with this with a bad tank of gas.. just glad i didnt spray

 

Stupid question, but: Where is the ICM and how do you check it?

I've been getting alot of random misfire codes, and the plugs and fuel filter have been changed.

 

mine has done the same thing three times now but luckily it was 8 months or so between times.. First was under warranty, the last two times have nearly cost me $1000

mine is the 06.. Im pretty sure the last time they replaced the ICM