Misfire and EGR Codes

[zzpw3x]

So I've been dealing with this for months and making no progress.

I started with P0401 (EGR) and occasionally it would miss when cold (or I perceived it as missing - it would run poorly on cold mornings). I replaced the EGR (and DFPE). Fault returned. I replaced the PVC. Fault returned.

Eventually, I started getting the P0301 and P0316 (and P0401, followed by P1000). Missing at startup became common.

I replaced the 3 ignition coils on the passenger side only and ALL spark plugs and all gaskets in between. Also replaced the the IMT valve gaskets. Why only 3 ignition coils? Because they are expensive, and the P0301 code should have been resolved. Faults came back, and it still ran poorly when cold, so I replaced the other 3 only because I didn't know what to do next. Faults came back, but runs good when cold. A cheer for small victories.

I have looked at the vacuum hoses. They look good but I guess I need to do better inspections.

Any thoughts?

 

[Telco]

Assuming you have a V6. The LS, at least the V8, is very sensitive on coils, or COPs. If you need to replace one you have to replace them all, and all spark plugs, at the same time. When one of the plugs or COPs go they don't want to be lonely in failure-land so they take all their friends with them.

On the EGR, was it the factory piece or one of the generic parts store one size fits none jobs? If not a factory piece, it may make the situation worse than the failed factory piece was. Replace with a Motorcraft piece.

Next up, the plastic vacuum lines can be split but imperceptible. You can pick vacuum leaks up by using a propane torch. Turn it on but don't light it, and run it along the vacuum lines. Any rubber pieces can look perfect, but be dry rotted and leaking like a sieve. You can tell this by rubbing your fingers across it, if it leaves a black streak on your fingers that doesn't want to come off, you've found a leak.

Finally, what octane are you running? The LS, at least the V8, doesn't like anything other than 91/93. If you're running 87, you're doing it to yourself.

 

[joegr]

If you have a V8 you need ALL of these items. Denial will only hurt you!

http://www.lincolnvscadillac.com/forum/showthread.php?97772-LS-Maintenance-items-for-sale

Well, if he really replaced the PCV valve and the IMT valve gaskets, it's a V6 because the V8 has neither of those. (It's fairly clear otherwise that he is talking about a V6. It would be really nice and help with the advice he gets if he would tell us if it is a gen I or gen II.)

Edit: Oh, now I remember zzpw3x. Never mind...

 

[zzpw3x]

Sorry, I always seem to forget to detail what I have.

It's a Gen II V6.

I was overly optimistic about the missing when cold being resolved. It's still a problem.

All replaced parts were motorcraft parts except for the gaskets which were VICTOR REINZ. Fuel is 93 octane. I appreciate the thoughts so far and will look more closely at the vacuum lines.