1997 Dodge Neon (Code 11) - P1390 or P1391: Timing Belt Skipped Tooth or CMP/CKP Sensor Issue?
I have a 1997 Dodge Neon with DOHC engine. The check engine light is on, preventing me from passing the emissions test. The only stored diagnostic code is '11', which according to my service manual could indicate either: - P1390: Timing Belt Skipped One Tooth or More - P1391: Intermittent Loss of Crankshaft Position (CKP) or Camshaft Position (CMP) Sensor A previous owner used a code reader and reported the code as P1390. However, I recently inspected the timing belt and confirmed it is properly aligned and not damaged. I have reset the Powertrain Control Module (PCM) multiple times, but the code returns after just a few miles of driving. What specific tests or components should I check to diagnose this issue accurately?
Inspect the wiring harness connected to the crankshaft position sensor and camshaft sensors—oil leaks around the O-ring are common in this engine, especially near the valve cover. Crankshaft sensors can also fail intermittently. Make sure the timing marks are properly aligned; DOHC engines can be tricky to set correctly. The wiring harness behind the engine, particularly near the alternator and other components, is a frequent failure point. Good luck—please update if you find anything or get further results.