i scan my car with odb2 all cylinders was missfires and another code of 1399 manfacurer ignition. so i changed 4 spark plugs engine run fine...but light pop up again. this time its just 1399 only, so can anyone tell me what might be the problems still? thank you

 

Bent valve!

 

And ask me how I know

 

Could it be a coil pack? Just throwing ideas out there.

 

how do you know?

 

dont worry about the CEL.. i've been driving around with it on for the pass 2 years. I heard it adds hp anywayz