Code p0340, sensor replaced, check engine light still off, but backfiring...help!!
I have a 2003 4.6L GT with 92,000 miles. Last week, we had the dreaded code p0340 (camshaft position sensor). Along with the check engine light, the car was backfiring at start up, gas mileage dropped significantly and car felt sluggish. We tried for the easy fix and replaced the sensor and cleared the code. For about the next 5 times that we started the car, it still backfired, but the check engine light didn't return. Then, the backfiring stopped. We assumed that it was just the computer relearning. Then again today, the backfiring at startup began again. Stilll no check engine light.
We have read multiple threads and posts that say that the alternator can be a culprit, however, what concerns us is the fact that the check engine light hasn't returned. Is it possible for the alternator to be confusing the sensor but not triggering a check engine light?
Any thoughts or suggestions for other things we should check?