P0300 Chrysler -

Question

There is no power loss , start up with no problem ,idle is great,reset code and 1 min. later it returns, but the car runs great, p0300 is still there

Answer 1

P0300 Random misfire

When the ECM codes a P0300 it uses the crankshaft speed varaition to detect misfire, when a mifire occurs the crankshaft signal is slowed,  Anything that affects the speed of the crankshaft can cause a P0300 to set, this can be from binding water pump to the a/c compressor binding,, to a vacuum leak right near or at the MAP sensor. even the fuel injector .The worst possible scenerio is when the ECM shut down that particular injector for the misfire. Check the sparkplugs, and use the underhood sticker for the sparkplug that is used.

Here is a Chysler 2.4 PT cruise, the owner recently replaced the sparkplugs using the required sparplugs, but after the tune up a P0300 showed up, when checking the spark plug condition what was found was  that all the sparkplug where not tighten down,this one came out with just a extension and a sparkplug socket just using hand.The loose sparkplug caused a improper sealing during its combustion.and its intake stroke