You getting a flashing CEL, CEL codes or just "feel"?

If you don't know the age of the plugs, should consider replacing (qty 8, OEM style DENSO or NGK only).

There is one coil pack per spark plug. I had to replace one. RockAuto has the OEM style (Hitachi made) for about $45. I had the luxury of swapping packs between the two cars before I committed to a replacement.

Good luck,

Steve

 

Thanks Keith. Car had 228000 on register when I bought it. Now has 233000. I have a parts car, so I can do your procedure with the coil packs.

 

Totally forgot about that. Since it's a bit of a pain to get the driver's side rear pack out, I swapped out only the front, and I got lucky.

HCH2 #2 had about 212 on the clock when we got it in 10/14. The plugs were absolute toast. Flashing CEL (active misfires) and misfire codes on all cylinders. New plugs cured all the misfire codes, but there was a slight "stumble" or hesitation that was noticeable under any significant acceleration. The new coil pack fixed that.

Have you cleaned out the EGR ports? Your high mileage almost guarantees it needs it as it's likely not been done.

 

Got both cars pulled front to front in shop. New plugs first thing in the morning and if it still misses, then to coil pack swap. Thanks.