P0400 Fault in 2001 Chevrolet Cavalier: Loss of Power and Starting Issues
My 2001 Chevrolet Cavalier with a 2.2L engine suddenly lost all power while driving, as if the engine had completely shut down. I was pressing the accelerator pedal hard when this happened. After replacing the starter motor, the issue persists. The car will sometimes start and drive fine, but then lose power or stall—sometimes it starts immediately after stalling, other times there's no click at all when attempting to start. I've taken it to three different mechanics with no resolution. This is extremely frustrating as my vehicle keeps stranding me. My code reader currently shows fault code P0400. I'm seeking help identifying the root cause—could this be related to emissions or fuel system issues? Any insights would be greatly appreciated.
Does your OBD2 scanner read all fault codes, including P0999 and higher? Please check the freeze frame data—specifically engine vacuum readings. Code P0400 indicates an EVAP system large leak, possibly due to a malfunctioning purge or vent valve, such as a non-commanded purge. Have there been any recent modifications or new components installed? Is the vehicle stock in terms of original equipment and no aftermarket parts?