So I just did my head Gasket in my 02 GT 2V but afterwards it ran great no hesitation in driving idles great. But I'm getting a code for p0306 and another code p0316 (misfire found within first 1000 rotations) the car itself doesn't have any skips or chugs when idling or whilst driving.
Here's the other thing the code only comes up when the motor is hot, if it turn it off and restart it when it's up to operating temperature it sets the code. When it's cold there's no code. I've driven from cold start to all the way warm 30+ min no code. As soon as I turn it off and restart solid code. Another odd thing is it's not flashing like I've seen misfires do as well it stays solid on the dash. Now​ I do know the exhaust had quite a bit of water from a blown head gasket could that cause a catalytic converter to go out?
I've read that sometimes this is an issue. And before we ask "have you checked for spark, fuel, compression?" Yes all three check out just fine. They are operating normally. In fact I checked all cylinders for all three.
Read more: Misfire code in cylinder #6 after head gasket replacement but it's not a misfire? Ford mustang GT 2002?
