Hey guys ,new to all this.have been here before but never posted appreciate your advise. 2004 audi A6 3.0. I have a smog test problem.not only check engine light,but random misfires and each cylinder also had a cat code but went away also a coolant sensor code
now when I start first time in day it's rough and miss for a minute then smoothies out and runs great all day.love the ride...do you think I may have headgasket leak between cylinders ? And if so , is there any way to avoid pulling heads.....does not smoke.....thanks please reply.