I just bought an 05 Mustang GT. When I bought it, the check engine
light was on and for code P0340. I replaced both cam sensors, and the alternator as it was the original alternator. I don't have a check engine light on anymore, but I still have an issue.
Basically, when I first start up the car it runs great and has plenty of power. Once it warms up though, I will be coming to a stop and it will start massively misfiring. I will get moving again and at about 2500 rpm's the misfire will stop and the engine runs perfect again.
Also, I pulled the valve covers off and the cam phasers are both tight. I don't know if that is the correct way to test them, but there is no play in them. When the misfiring starts, it also sometimes stalls.
I am supposed to make a 300 mile trip on Wednesday and don't want to risk it if I cannot figure out what is going on.
I would really appreciate some help here.