Have this 01 Chevy Silverado 2wd 1500..has a hard time cranking when it's cold.. We replaced spark plugs and wires, alternator, fuel pump, filters, coil packs, battery, and the bank 1 O2 sensor. It threw the code for that and po300 code. Said to clean injectors and replace coils. Did all of that and she still runs hard in the morning for about 30 minutes then she levels off. Idle above 1000 at times. Other times she idles up and down then shuts off. Some days seems like the engine is about to jump out the truck..but has no issue while driving at all. Has total power and no problem accelerating. I don't know what else to do. The wife love this truck..it belonged to her Father. Please help me...in distress
P0300 means the engine is misfiring.
Check the fuel filter and measure the fuel pressure.
