Originally Posted by
Padgett
Really need to download the service manual, makes things much easier. P030x is not deactivation. It is an unplanned rpm loss. 9-343 in '05 SM.
(P0300) MULTIPLE CYLINDER MISFIRE (CONTINUED)
Set Condition: When more than a 1.0% misfire rate is measured during two trips.
POSSIBLE CAUSES
ENGINE CONTROL RELAY OUTPUT CIRCUIT
FUEL INJECTOR CONTROL CIRCUIT
FUSED IGNITION OUTPUT CIRCUIT
ENGINE MECHANICAL PROBLEM
COIL ON PLUG
COIL ON PLUG DRIVER CIRCUIT
SPARK PLUG
FUEL STRAINER PLUGGED
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP
FUEL INJECTOR
POWERTRAIN CONTROL MODULE
For a complete Powertrain Control Module Circuit Diagram, (Refer to 9 - ENGINE - SCHEMATICS AND DIAGRAMS).
OK! this is really good feedback! It supports my theory that its a fuel pressure issue not a coil or plug issue.... I think I have a bad fuel pump and the car is shutting down random injectors to protect them when they are struggling to get fuel, and that would explain why I get a random misfire code and an ever-changing individual coil misfire code ... I will investigate this theory and report back!