I have a 2011 with a 2.2. It started running real rough the other day, threw code p0302, misfire no. 2 cylinder. I replaced the coilpack and the problem went away. 2 days later does it again but now it is a misfire in the no. 3 cylinder. Is this just coincidence or am I chasing a different issue?

 

Swap coil from 2 to 3 and see what the results are.
#2 is a known good coil.
How many miles on car ?

 

Mileage?
Is there a reason you replaced the coilpack ionstead of the spark plug?
Did you do any diagnostics? Like switching coils?
What spark plugs?

 

How many miles on the spark plugs? I'm guessing that it's an intermittent spark plug issue. Replacing the coil only seemed to fix it.

Spark plugs wear out, coils, not so much.

Injectors also wear out(or clog, or just fail), intermittently, so the same reasoning could point to injectors.

For these reasons, I think swapping coils would be inconclusive.

 

Car has 110,000 miles on it, both the coil and plugs have about 40000 miles on them. I replaced coil because i had one available.

 

Why were the coils replaced? Not a normal tune up item.
ACDelco Iridium plugs? Others don't work well.
Compression test.

 

they are ACDelco Iridium plugs. When I got the car I went trough and replaced the coils, plugs and air filter. All OE parts.

 

Reasons for misfire:
plugs
coils
burned valve
blown head gasket
vacuum leak
low fuel pressure

Reasons for false misfire code:
Crankshaft position variation not learned
wheel balance/bent
damaged serpentine belt

 

She’ll misfire also when the timing chain guide starts to crack and break up . Also when the timing chain stretches and is ready to skip a tooth!

 

Swapped the coil and now it is running normal