I just recently bought a 2004 Mazda 6i 4cyl 5spd 100% stock. I bought it from a used car dealer, and it looked and ran terrific. I drove it home, did fine all the way home. parked it and left it til the next day. I got in to start the car, and the car ran horrible and misfired and ran like it was out of time for about 2 minutes. after that it ran perfect again. I ran the CEL that it threw, and it said it was a Camshaft Position Sensor. The dealer said they had just replaced this, but i figured it might have been a faulty one from the factory so replaced it again. next day comes and same thing happens. the car runs perfect after you start it, and even if you shut it off and start it again, runs fine, however if I leave it sit for 6+ hours then it runs like crap when i start it? all the wires on the CPS appear to be fine? I am needing some serious help. this is my first Mazda, and so far I am not impressed at all someone please throw some ideas at me, the only code it is throwing is the CPS code.

Michael

 

Crank Position Sensor is known to be bad when car doesn't start properly. It gets very dirty especially with a standard.
Position of Cam is dependant on position of crankshaft, if crankshaft off then cam position will be off.