* No Start: This is a primary symptom. The engine won't crank or turn over because the computer needs the CMP signal to know the engine's timing.
* Hard Starting/Rough Starting: The engine might crank but struggle to start, or start and run roughly.
* Misfires: The engine will run poorly, possibly with a noticeable stumble or shaking. You might see a check engine light illuminated, and a diagnostic code related to misfires.
* Check Engine Light (CEL): This is almost guaranteed. The CEL will illuminate, and a code reader will display a code related to a camshaft position sensor circuit malfunction.
* Stalling: The engine might stall unexpectedly, especially at idle or under light load.
* Poor Fuel Economy: Inefficient combustion due to incorrect timing can significantly reduce fuel efficiency.
* Hesitation or Lack of Power: The engine may hesitate or lack power during acceleration.
Important Note: Many of these symptoms are shared with other problems (like a crankshaft position sensor issue, ignition problems, fuel delivery problems, etc.). A proper diagnosis *requires* using a code reader to retrieve the diagnostic trouble codes (DTCs) from the car's computer. This will help pinpoint the exact problem. Simply replacing the CMP sensor without confirming the code could lead to wasted time and money if the problem lies elsewhere.
