And we are DONE! Purrs like a REALLY big kitten! No more SES light, still have ABS but thats sensors...Replaced all 10 plugs with autolite plats, didnt need to replace any coils, all their resistances checked sat against the numbers in the Haynes manual. Several of the plugs I pulled were way over gapped, and some of the coils seemed like the springs were stuck up in there and not making contact...
Anyway...10 plugs, a few new toys..er..tools.., PCV, EGR and DPFE...6 codes cleared.

I've decided I am going to let the dealership do the Headers...need the warranty.

 

Congrats on the plug change!

I've had tech problems or I would have jumped in sooner....

Just be sure the coils are plugged in securely - I had #4 come loose while towing last fall.

 

I'm not looking forward to this... 50K to go

 

Its not that bad. Just do your research before you start and don't get in a hurry when you're doing it and all will go well.

 

How many miles on your current set of plugs? I wouldn't go past 50K before checking and/or replacing them in these motors.

Maybe I misunderstood something?

 

Well..

Changed the plugs and checked the coils...

Still shuddered a little bit, but I convinced myself it not a misfire, must be something loose...like the Exhaust manifold!! $630 later, manifold is on great, new gaskets, studs and bolts...and we're still shuddering..

I'm gonna have to say its a misfire..again..but no codes.

Can I get a list of possible suspects in order of probability..

These are the codes I pulled before I DC'd the battery..
p0171, p0401, p0303, p0304, p0308, p0354

Thanks.

 

Well, 303, 304, & 308 are misfire codes on cylinders 3,4, and 8.

I suspect that you have some bad coils on there. Before you run out and buy coils, check the boots and springs to make sure you've got good contact between the coil and plug.

 

My shudder at lower speeds turned out to be the lock up trans converter. If you replaced spark plugs this might be something to check out.

Just a thought: Bob