Also, since you just replaced the intake (and probably the plenum gasket) I have had luck reusing my plenum gasket with no leaks as long as I sprayed it with copper coat gasket compound... Save a few bucks if you decide to check the injector.

 

This was the best lol, thanks OG. I've tackled a few of theservice issues dealing with the P0307, and now have a few more tricks to try!

 

Lots of great info in this thread! I'm tilting at the windmill called misfire currently. Here's the story and process to date:

04 D2 with 160K. Recently started misfiring after getting rear-ended. Maybe not cause and effect.

Replaced and relocated the coils and put in new Kingsbourne 8mm wires and all seemed well for a few weeks.

Took the truck on a trip. Trying to make the ferry, under load, multiple cylinder misfire. Catalyst damaging etc. Got to to the other side of the ferry and friends helped me change the head gaskets(local shop found a leak). We Also changed the plugs. MAF had already been changed the month before. No vacuum leaks. SAI valves and pump new.

Truck ran well for about a week after. Misfire returned. Cylinder 1 and 6 along with P1300.

Today, I replaced the CPS to see if that would help. Doesn't seemed to have. The only other things I can think of are fuel injectors(which I hear is a rare failure) or a flex plate failure(which one of the online parts specialists told me they've seen).

She's my daily driver, although not currently. I'm not one to throw in the towel, but I'm getting close. I'm going to pull the plugs on Cylinder 1 and 6 tomorrow and see how they look. Will also look at the pins on that coil to make sure they're clean.

Any other suggestions or words of encouragement are certainly welcome at this point. :-)

 

I think the first post in this thread should probably be edited. I'm pretty sure I've gone through this thread a few times without ever seeing this. I'm really thankful you posted your solution here though, for me to finally see it and check my coils.

I've been doing stuff for a cylinder 8 misfire for weeks now trying to get to the bottom of it. Most recently, changed injectors (in the meantime changing the valve cover gaskets (in the meantime breaking that blasted plastic hose junction thing that goes into the water pump and replacing it with an aluminum one)).

The funny thing is, I did the coil pack relocation when I changed the spark plug wires, so I have them right out there where it takes 1 minute to swap them and test, but I didn't even bother to do it, because I'm pretty sure I saw other places on the forum saying that if the coil packs are bad two cylinders would be failing in unison because of the wasted spark system. So, I didn't even bother to check. Today, when my check engine light came on again, I was reading through this thread in despair and happened to see this post. Went out just for the hell of it and swapped the coil packs. Lo and behold, the misfire moved to cylinder 7 !!!

Found a replacement set of two coil packs with a lifetime warranty at O'reilly's for $70, going to pick them up in the morning, God willing.

 

By the way, how was the shop able to test the coil pack without removing it?