Sratching my head. Had a set of used cats installed and she pulled and sounded like
a race horse and fixed the missfire. She passed emissions with no prob and the o2s
were working properly but as time went on the sound and power went back to when
the cats failed.We're talking 3-4 weeks . Have another set of cats with less km's but want to be sure the o2's or something else i'm not aware of, fraking up the cats. I have a Magnaflow exhaust
and it sounded like a Vr6 VW and not a 4 cyl with a drone like today. Do I just switch
to the other cats or sould I look into the air fuel mix or timing? Don't want to go back to dealer
and throw more money to diagnose switching o2s. And the obvious ticking from the
injectors has me wondering a lifter could be the prob. I'm already turning to
a glen wiskey of some age to help me through this tough time. Cheaper to buy new cats. lol
Change oil and filter and cats?