I have a 2007 charger SXT 3.5 L with 160,000 miles on it. I bought as a "low compression" vehicle. The car wouldn't go over 30 mph, had no compression in cylinders from leaking, not bent, valves. It was also running really rich and the spark plugs looked awful with black soot on them. Had a code p0300 random misfire. I put refurbished heads on with all new gaskets, timing belt, and plugs. The pre-cat in exhaust flange looked restrictive so I removed just the pre-cat on both side. The timing is set correctly. Everything back together and it still runs awful. Spits black wet soot out tail pipe, drivers side plugs are all black like it's still really rich, and passenger side all look okay. Basically the same as before, still goes into limp mode when driving, max rev is 4000rpm(maybe that's normal in park?) it sounds like something clanks once in awhile. Possibly unburnt fuel igniting in manifold? I am stumped. I've reset the ecu. I'm close to taking in to a shop, but thought I'd give the forum a try first. Took the plenum off and could see gasoline puddles on every intake valve on driver side. And passenger side intakes were dry. Any ideas, tests, or anything at all I can try? Thanks everyone