well its not that simple, the car gave me this code about 4-6k miles ago, so I changed the plugs code did not come back until a few weeks ago. so last weekend I figured I'd swap the cols from cly 1 and cly 2 to see if this cured the problem or if the code would move to cyl 1 (making it a coil pack problem) and the plug looked good, well it did not still reading cyl 2 misfire what should I check next

 

Rotate the plugs now and then maybe the injectors after that to see if the problem moves to a different cylinder.

 

Next swap 2 injectors

 

UPDATE: I swapped injectors 1 and 2 dove it for a while engine light stayed off the next day will driving around it came back on, so I swapped plugs 1 and 2 looked at them booth neither looked any worse or better than the other checked the gap on both and reinstalled. Drove it to work yesterday no light drove it again this morning and it came back on, same code p0203.....any more ideas? oh one other symptom after the engine light comes on the tranny shifts hard.

 

Compression test. Or try swapping coil packs with someone.

 

U seem knowledgable but ill say this anyway. The 3 things you check when checking for a misfire r 3 very broad subjects ha. Fuel, spark, and compression. Seems like u ruled out spark. I agree id try swapping the injectors and seeing if the misfire moves cylinders. If u havent already. If that doesnt work id probably go to checking for evidence of mice chewing wires. But something that could help u rule some things out would be telling us when it happens. All the time, under hard acceleration, only when cold, only when hot, etc. let us know that and im sure some experienced guys will chime in and get this figured out pretty quickly

 

You've swapped plugs,coils and injectors and still have a misfire on cyl 2.
Check very closely the wires leading to the injector for shorting follow it all the way back as far as you can for chaffing and or bare spots that might be shorting or anything that looks like a likely spot.
Another thing inspect the connector as well for bad or loose fitting pins and bad connection of the wires to the pins( tug on the lightly )

This was a know issue with alot of the older ss sc models and caused the same symptoms!

 

Swaping coil packs is eayser then swaping injectors

 

he already said he tried swapping coil packs. diagnosing a misfire isnt always "easy". alot of the time its be some sort of spark issue but for the times it isnt. id love to see u figure it out mr. "i take the EASY way out"

 

Like said, after checking spark and fuel the next to check is compression.

If all that checks out, check all wires and harnesses to everything pertaining to cyl #2.

 

yep everything has been swapped between cyl 1 and 2 coils,injectors and plugs..... checking the wirein is next althoug I know its not mice or squirrels...the car dose not sit long enough....

I wish I could tell you it happens at a certin point every time but it dosent..the other day did it cold, the last time drove it for a few days nothing and then it did it on the way home from work it's, irratic and is was bothers me most...

but next I'll check the wiring and check compression....dose any one know what the compression rate is on the 07 2.2 ecotech or where to find out? thank every on I'll keep you posted

 

I had a mystery misfire on cyl 3 a while back. It turned out to be a slightly exposed wire on the coil pack harness that was contacting the block.

 

It's a known problem with the older models .Ive seen the Tsb my self on it.
I think it says to check the injector wires where they pass by the purge selinoid bracket .

 

there ya go. it isnt definitely it but give this a detailed look