I got 18 dodge durango v6 3.6 problems I having is I have p0300 and p0301 with 88k thousand on it, replace both Battery, spark plugs, coil packs, injectors, pcm, and done compression test and I keep having issues of random missfire. I get random misfire when at high rpm only I don't know what to do now it's frusting and annoying

 

Welcome to the forum. So is the P0301 now fixed and you're only getting the random misfire code, and it only triggers at high engine speed? Does the engine seem to run completely fine, or do you feel the misfires at high engine speed?

I'm not very familiar with the 3.6L Pentastar, but considering everything else you've replaced I would first suspect a camshaft position sensor issue or possibly a crankshaft position sensor. I recall with at least older Fords a missing crankshaft position sensor signal will cause stalling and/or a no start condition, and spark and fuel injector pulses were controlled off the camshaft position sensor. I also recall older Mopars had a Crank/Cam Synchronization routine that could be performed with a high end scan tool to help and that could help with random misfire situations. So I'll suggest you look at the camshaft position sensor (there may be more than one) as well as the trigger on the camshaft(s). If nothing is apparent from that, then do the same with the crankshaft position sensor.

-Rod

 

I replace cylinder head and camshaft rocker and lifter cause that's was problem now I'm having issue where misfire continues but not having any issue shifting or working hard only on slow down misfire happens

 

So you replaced the head and associated parts since your first post, and now you still have a misfire, but at low engine speed now instead of under load at high engine speed? Are you still getting codes for both P0300 and P0301? Which head did you replace (Bank 1 or Bank 2)?

-Rod

 

I would recommend changing your computer. This controls all fuel and timing. Have your mechanic check your engine codes. Good luck

 

I think it might be a bit premature to suggest replacing the computer.... Especially since the computer is recognizing misfires. If it was failing to communicate with the scan tool or obviously misfiring but not triggering a code, then maybe.

-Rod