P0340 and P0344 Fault on 1999 Ford Mustang GT - How to Fix After Replacing Camshaft Sensors and PCM

Model: 99 Mustang GT Fault Code: P0340 Posted: 2020-12-01 01:06

Hello, I'm experiencing persistent check engine light issues on my 1999 Ford Mustang GT, specifically with fault codes P0340 and P0344. I've cleared the codes using an OBD2 scanner, but shortly after starting the car, the check engine light returns immediately. I've already replaced both camshaft position sensors, tested the alternator, inspected all wiring connections — everything appears to be in order. A mechanic recently replaced the Powertrain Control Module (PCM) as he suspected it was faulty, but the issue persists. Given that these codes are related to camshaft position detection, I'm wondering if there could be another underlying cause. Has anyone else encountered this problem on a 1999 Mustang GT? Any suggestions or troubleshooting steps would be greatly appreciated.