2006 Jeep Wrangler TJ P0340 and P0344 Fault: Cold Start Stumbling Resolved After 3 Miles of Driving
I own a 2006 Jeep Wrangler TJ and am experiencing consistent cold-start issues. The vehicle starts about 95% of the time, but sometimes requires multiple attempts. When driving, it stumbles significantly during acceleration—only responding to very light pedal input. Once I drive for approximately three miles, shut off the engine, wait five seconds, and restart, the stumble disappears and the vehicle runs smoothly. The check engine light is illuminated, and a scan reveals fault codes P0340 and P0344. I have already replaced the camshaft position sensor (CMP) with no improvement. My suspicion now leans toward a wiring issue or faulty connector in the sensor harness. Notably, if the ambient temperature exceeds 60°F, there are no issues—no check engine light, no stumbles, and easy starts. However, when temperatures drop into the 50s and below, the CEL activates immediately, cranking time increases, and the vehicle stutters during acceleration. After warming up fully, shutting off and restarting resolves the problem completely.
I've been experiencing a similar issue with P0344. Cold start causes slight bucking, and the code appears—clearing it temporarily fixes the problem. However, if I let the engine warm up for 5 minutes at idle or drive normally, the error doesn't return. I haven't replaced any parts yet, but I've confirmed the battery is under warranty and have unplugged and reconnected the camshaft sensor to rule out loose connections.