throw p0301 - replace coil pack - throw p0301 months later, thoughts?

[spaber05]

Hey guys, subject says it all really. Threw p0301 late last fall after slight shuddering on a gradual uphill, replaced coil pack on cyl. 1 with new OEM, end of story...or so I thought. Threw p0301 again last weekend driving some similar hills, similar shuddering symptom, but CEL was NOT flashing this time around.

Let me know what to look at next as it is probably not a faulty part. I had to take it to a shop to get scanned and they said to check the ground for the left bank, which I did, but it looks find to me. Any other thoughts would be appreciated, really would like to have this figured out sooner rather than later.

Thanks guys!

 

[Lowbudgetlc100]

trade coil see if it does the same thing

 

[spaber05]

Yeah that's on the list, but it took a while for the code to come on again. Is there anything that I can do immediately to check other failure/weak points?

 

[pavieSD]

Check the wiring to the coil pack. Maybe it's arcing somewhere causing an intermittent condition. But if swapping the coil pack moves the error to the new coil location then you know it's a bad coil. It's also possible you didn't install/seat it all the way causing the intermittent condition as well.

 

[spaber05]

Ok, re-seating was my next move, I'm pretty sure it's on there properly but never hurts to double check. If it's clipped in properly I'll swap them around and try to recreate the conditions that caused the CEL in the first place.

 

[AimCOtaco]

You could read the plug, perhaps another combustion problem under load is showing up as p0301, a fouled plug, clogged injector, bad spray pattern, sticky valve, many other things could lead to the ECM showing the code..