Random misfire
#1
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Random misfire
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?
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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?
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?
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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.
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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.
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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.
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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.
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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...
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edit: scratch that, the previous owner did the bpv tank mod
Last edited by spina74; 08-25-2012 at 01:55 PM.
#16
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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.
#18
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?
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I really hope not, or the cars gone.
#24
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.
#25