P0300 and P0302, HELP!
 

Hey guys, let me start off by saying that I have searched the forum for these codes and read each page of each article. With that being said, I changed out my coilpack and plug, and even tightened the pins in the connector on the coilpack yet the car still has a misfire in cyl 2. I have no idea what else could be causing this. Mods are stillen gen 3 with dry filters, berk HFC and HKS HI-Power exhaust. Anyone has any input on this issue that can help? I'm wondering if to take it to the dealer but my car is slammed and i'm not sure if they'll turn me away due to the mods.....
Any help is greatly appreciated
Thanks

Also cleaned out the MAFs with a MAF cleaner and didn't touch the hot wires, misfire still there....

Check the coil/plug connection.

MAF problems will (usually) affect the whole bank, not just one cylinder.

Dealer could possibly refuse warranty on your suspension but not other items that haven't been modified.

Thanks man, already checked the connection several times, didn't help. Spark plug I removed smelled heavy of fuel though. Would that mean I have to change the other plugs and coilpacks on the same bank?

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That sounds like the plug is still not firing. Check the primary side with a VOM (may take a sensitive meter to see the quick pulses) and make sure the coil is being pulsed. FWIW, the plug fires when the coil is de-energized.
Not sure how you can check the secondary side. Back in The Good Ole Days, we just laid the spark plug on the block and looked for a spark.

It sounds like it is only the one cylinder messing up, so the rest of the bank is probably OK.


You may have a fuel injector problem.

I would probably lean towards a stuck injector, thats assuming your definitely getting spark.

Thanks a lot guys, going to check it out this weekend and see whats going on. In the event its not the injector, anything else that may lead to this issue? Has anyone pulled off the manifold and changed the injectord themselves? Wasn't able to find a DIY

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Yes I have you just pull the plenum off and then you can pull the rail it's pretty easy.

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A wet plug is a sign of no spark or an over-active injector. I can't think of anything else that could cause your symptoms. Maybe someone else can come up with something.

Initially the plug smelled heavy of fuel and was pretty much done. Changed that and the coilpack and symptoms still continued

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What was the outcome of this? Im having the EXACT same issue, and none of the basics.