2000 Olds Alero 2.4L P0507 Diagnosis: Idle Control Issues After Coil Pack and Ignition Replacement
Hi everyone, I'm having trouble diagnosing a recurring P0507 code on my 2000 Oldsmobile Alero 2.4L. After recently replacing the coil pack, ignition control module, and ignition switch at a dealership, the check engine light came back with code P0507 — indicating an idle air control issue. I've already checked for vacuum leaks and found that the PCV hose wasn't properly reconnected, and the clamp on the throttle body was loose. I tightened it and reset the ECU, but the P0507 code has returned. When I sprayed around the injectors during testing, the idle speed changed — is this normal behavior? I also replaced the injector O-rings last year, so I'm surprised to see a vacuum leak here. Could the dealership's work have introduced or exacerbated an issue? Are there other potential causes I should investigate? Any insights or troubleshooting steps would be greatly appreciated.
Leaking injector seals allowing air into the intake manifold could be a significant source of vacuum leak — this is at least one potential cause to consider. Other possibilities include: vacuum leaks, air intake leakage after the throttle body, EGR valve vacuum leaks, a faulty or clogged PCV valve, damaged or dirty throttle body, failed EVAP system, or a malfunctioning idle air control (IAC) valve or its circuit.