Thanks cricket and Matt for the replies. In addition, I switched around my ASD relay with another relay in hopes that maybe an intermittant relay was causing the interuption in fuel, but it didn't work either.

Quote Originally Posted by criket View Post
Going out on a limb here but on the Liberty's and on the Liberty forums, the 3.7 V6 has a problem of breaking valve springs, weak valve springs, etc. on valve springs. One of your Intake valve springs could be broken or worn so bad that the Intake valve isn't closing properly and could be throwing the miss fire code.

Of course that's a big if. How are your coils on each cylinder? Could one of some of them be bad causing the miss fire?
I hope it's not something that serious. I'd think if it was a bad spring or a bad coil that it would throw a specific cylinder code rather than the general P0300 code, but I'm not sure how the computer actualy identifies a misfire. I can't imagine multiple coils going bad at the same time. Although lately I'd believe almost anything.

Quote Originally Posted by Matt View Post
P0300 is not a good code to troubleshoot on electronically controlled ignitions. More often than not, its an ECU issue when the plugs are fouled like that (otherwise normally a fuel supply issue).

Did you put new plugs in?

Have you changed the PCV valve? That seems like a log of excess blow-by in the intake.
I did change the plugs but not the PVC valve. I did run out tonight and picked a new PVC valve from O'riely's, I'll swap that out in the morning (I like the cheap fix options).

As far as it being an ECU issue, would that be fixed by reloading the factory tune (I was running the Hypertch tune) and in this whole process have reprogrammed a few times both the factory tune and the Hypertech tune. -OR- would a dealer have to reflash it? Or is it possible that the ECU itself is bad and needs replaced?

Matt, when you say fuel supply issue, are you thinking fuel pump issue? or injector issue?

One other thing I saw somewhere was that carbon buildup on the exhast valves can prevent the valves from seating and sealing completly and create the problem. Compression testing could help identify this issue. You don't happen to know what the cold compression numbers should be on a 3.7 and how much variance between cylinders is within standards do you?

Thanks again for the help.