I have a 07 Cobalt ss. i have been having trouble with a check engine light saying cylinder2 misfire, and bank 1 lean. the car has only 14,000 miles, The light seems to only come on throwing these codes when i run it hard. or it boosts up. does anyone know what might be causing this?

Mods:
GM stage 2 kit
Vibrant Header and back Exhaust
Aem Cold air
Cold plugs NGK
H&R Sport Spring

I want to see if i can get an idea of whats going on before i bring it in to the dealer. so if any one has any ideas please let me know.

 

First check for vacum leaks on all hoses and fittings on your cold air intake. If it is behind the MAF then you will have unmetered air entering causing the lean condition. Also check if you have an intake leak around the #2 cylinder, an intake leak here can cause a lean misfire.

 

I figured it out. some dumb ass at gm didnt put the right Oring on the cylinder 2 injector so i was losing boost and fuel around that injector. it just wobbled around in there.