* Hard starting or no start: This is a very common symptom. The engine computer relies on the CMP sensor's signal to know where the pistons are in their cycle to initiate the spark and fuel injection. Without this information, it may not be able to start the engine at all.
* Rough running or misfires: An inaccurate signal from the CMP sensor leads to incorrect timing, causing the engine to run roughly, misfire, or hesitate.
* Check engine light (CEL): This will almost certainly illuminate, usually with a code related to a camshaft position sensor circuit problem (like P0340, P0341, P0345, or similar, depending on the specific sensor and problem). You'll need an OBD-II scanner to read the code.
* Reduced engine power: The misfiring and poor timing resulting from a faulty sensor will lead to a noticeable decrease in engine power and acceleration.
* Stalling: In some cases, the engine may stall unexpectedly, especially at idle or under load.
* Poor fuel economy: Inefficient combustion due to incorrect timing will result in lower fuel efficiency.
Important Note: Many of these symptoms can be caused by other problems as well, such as a bad crankshaft position sensor (CKP), ignition coil, faulty wiring, or a failing fuel system. A proper diagnosis requires reading the diagnostic trouble codes (DTCs) with an OBD-II scanner, followed by further testing by a mechanic. Simply replacing the CMP sensor without confirming it's the actual problem could waste time and money.
