Thanks Oscar. My local dealer doesn't stock ANY of the parts I need. Which is fine since I don't enjoy getting raped through my wallet. I did manage to find a Dorman version of the grommet, which is plenty tight. It seems to have smoothed out the idle, so there was a vacuum leak there, but the bucking and shuddering and pinging continue after the van has been running a while, which tells me that when the EGR system opens up, it introduces these problems. I get worse problems when the weather is wet, so it still could be a cracked coil pack, but I'm thinking that the DPFE is the likely culprit now, or at least I'm hoping its that easy. What are some indications that the DPFE is bad? The guy at the store who read my codes mentioned a Delta Pressure Feedback issue, but wasn't more specific, and the codes don't directly address the DPFE.
I still need to change the plugs and wires, so I'll pick those up. I think I'll be opening up the upper intake plenum and checking the isolator bolt heads and EGR ports in the lower intake when I pull the cowling to check the back of the EGR vacuum tube to manifold connection. Do those isolator bolts go bad once they're replaced? Anyway, thanks again for your help and I'll repost later when more is apparent.
Quote:
Originally Posted by olopezm
The faulty DPFE's are the metal silver ones so you might want to check that; however, I would focus on the EGR valve vacuum line and PCV grommet first.
The PCV valve should not definitely pop out just like that, so find a new grommet and replace it.
Follow the EGR vacuum line towards the back of the intake manifold. I had a problem with it and became undone. Make sure it's properly seated and preferably put a zip tie on it to prevent it from coming loose again. Other than that, make sure the EGR tube (the one that connects the EGR valve to the exhaust manifold) isn't cracked. If everything is OK I would suspect the DPFE might be at fault.
Misfire could be either the vacuum leak, clogged EGR passages (you would have to remove the upper intake to check that) or a faulty coil pack, which are also a known problem in our models. You can inspect the coil pack by removing it and looking at the back of it; if you se any cracks on it, then it's gone bad and you need to replace it. Although I recognize that a cracked coil pack would more likely cause misfires in two cylinders at once, it doesn't hurts to check.
Oscar.
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