Since I got my cobalt I've had a flashing CEL here and there that went away after the car started to move. I changed the plugs and the issue went away for a while. Now its back again and happens every time i come to a stop for more than a few seconds. Is this a common issue and what else other than the plugs should I look into?

 

Have you been attempting WOT runs or NLS when under engine operating temperature?
It's really hard to say, are you running different plugs? I've heard people running anything other than NGK or OEM having issues...

Give us some background, used/new purchase? Mods?

 

Make sure you don't have Denso plugs, they are NO GOOD. NGK/ACDelco Iridium is what you need/want/must have in there :-p

 

No i never go WOT before its warm. The plugs are NGK iridiums. I bought the car used with a aftermarket ic and since then i installed a catless dp, forge bpv, and k&n sri. The flashing cel didnt fully go away after the plugs because it still popped up here and.there it just wasnt as common as it was before the new plugs.

 

Hrmm, any loss of power? Can you run a OBDII scanner and get us some codes if there are any?

 

Nope no loss of power, and nothing shows up when scanning even with HP tuners plugged in.

 

regap the plugs when u bought em? make sure they are all 0.32-.033 for the lnf.stopped my misfire.

 

I regapped them to .32 when I installed them. I've only ran WAWA 92 in the car. East coast guys know what I'm talking about. Would shitty gas cause a miss?

 

Just out of curiosity how long does the light flash? Meaning the time between when it comes on and then turns off and then back on again?

 

Are you tuned for all your mods?

 

check your coil packs?

 

The cel only flashes while I'm at idle mainly after I've been driving and come to a stop light then goes away after i start driving again. I'm not tuned for my mods, but when I got the car it only had an IC on it and it has a miss too. I've yet to check the coil packs. How would I test them if no codes are thrown.

 

Could be the intake skewing your trims dramatically. Make sure your filter is pointed in the correct direction. Could also be a massive boost leak. Yes you can still build full boost with a large boost leak, ask me how I know...

 

I have 2 hoses that aren't connected that run under the intake.....i have no idea where they go

edit: scratch that, the previous owner did the bpv tank mod

 

No hoses should be disconnected. Send a pic of them and their location exactly and we can tell you what they're for.

 

He did the vac tank bypass and left the tubing loomed, I bet.

OP: Like Faster says, I'm betting it's your fuel trims. Check for boost leaks, then get tuned for the mods and see what that does, or go back to the stock airbox and see if that helps.

 

Went back to the stock airbox, still has the flashing cel when i come to a stop, and I tried the different gas, still no luck

 

I see you're a 2008. How many miles are on it?

I'm just guessing maybe a fuel issue such as a dirty injector perhaps? Also very well could be a boost leak. Stock Charge pipes?

 

Run a compression check, sounds like a dead cylinder. (90 psi or less)

 

i change my plugs every year, the last coulpe mornings iv been get misfire after driving 15-20min, it looks like its time for me again

 

btw i thought misfire cels dont go away?

 

They do go away unless ECM detects more than 40 misfires (I believe) and then it
stores that info in the dtc's.

 

It has 48000 on it, and yea stock charge pipes.

I really hope not, or the cars gone.

 

this^^^^
AND when was the fuel filter last changed?


-easiest way to check the coil pack is to move the pack from the cylinder that is misfireing to another cylinder, take that one and put it on the misfiring cylinder. If the misfire moves to a different cylinder than chances are the coil pack is toast.

 

this^^^^ pic?