Parked my car last Wedneday and it was running great. Went to leave next day Thursday. It started right off the bat poor idling,stumbling. Drove around the block and still misfiring, stumbling. Check engine light came on and code came out P0300 and P0301. Changed spark plugs,wires and all six injectors and it is still doing the same thing. Changed the number 1 injector again with new one and still having the same problem. Checked compression on all cylinders 178-180 psi. What is going on.

 

Remember those codes are for that complete circuit .

Might be a problem in the wiring, connectors, ECM

What did the number one plug look like ?

What did the spark plug boot on number one look like ?? Was that changed along with the wires for #`s 2, 4 ,6 ??

PO301 is a miss on cylinder #1 PO300 often trips with any misfire



Have you swapped coil packs to see if the miss follows ??

 

what ended up happening here? throwing 300 and 303. (also 171 but am convinced that is a good ol MAF clean)