So this wednesday I got a CEL with the code P0303 (thanks Ultraguage!) which turns out to be a misfire on 3.....I drove it 5 miles and sure enough the car felt sluggish. Prior to this my idle kind of sucked for about a month but no pending codes or anything else to warn me.

Since the weather here in NYC was going to take a turn for the worse I ended up taking everything out leadiing to the coilpack (wiper blades, wiper motor, cowl, metal cowl, battery, PRM intake swapped with OEM (in case I had to visit a dealer afterwards), plenum......most of this job was taking the crap out to get to the packs and plugs, and reassembly of course.

And lo and behold the coilpack on three was filthy, covered in a black/brown soot that I would have to brillo to remove!!! there were deposits in the chamber which I vacuumed out before removing the plug. The plug looked good though...odd how easy it was to take out! It didnt even feel tight ....so I'm guessing there was some blow by that affected the coil pack....is that possible?

I still replaced the plug though and luckily had the spare set of packs from way back when I had the K&N issue and they determined the packs were fine.

Long story short, car is running REALLY well now. I took my time with reassembly and made sure to tighten all manifold and throttle body points to torque specs and noticed my Fuel trims look more normal than ever....single digits in average whereas I;ve been running 8-18+ on my ST fuel trims and 12 on my long term trim.

I also made sure to do the Idle-Learn as recommended by others on this forum.

Just wanted to share this story to see what others may have to share about the coilpack being so filthy (I checked the others and they were alll fine) and to give a heads up to any Fitfreaks out there noticing some lugging or hesitation.....may be worth your while to check the packs and replace the plugs.....

 

Thanks for updating.


Clifton

 

The brown stuff you saw was most likely from escaping combustion gasses from the loose plug.

Good job finding the problem and fixing it.