Help this problem happens with a cold engine.It runs like crap missing on a cylinder for about the first half hour until totally warmed up then it starts working normal.I do have a code scanner and pulled the PO320 code missfire on #4 cylinder but tested all the coils with a muti meter and they all test good.Anyone have an idea of what could cause this??

 

The coils can test good and still be bad. Swap the bad cylinders coil to another position. If the misfire changes cylinders, you have a bad coil.

 

Good advice.

Happened to me. Probably happens to everyone eventually.

 

I'm assuming you mean P1320.......and you've got the P0304 by the sound of it. The fault detection on this is almost murphy proof with those two codes. I just went through this exact deal, only it was #5 cyl. Just go and buy yourself a left bank coil and change #4, and clear the codes and you're done. And as mentioned, you can test these coils with a mutimeter until the cows come home......they'll appear OK, but it means absolutely nothing.

 

Ok thank you guys I will pick one up

 

I replaced the coil on the #4 cylinder and the car is running better than it ever has,No cel.Thank you again guys for your help.