Soo...I think I may have worn lifters. Due to an unnoticeable misfire I had a while back from the E3 spark plugs I used to have which caused my catalytic converter to break down inside and clog it. Do you think this could be the problem. I haven't dumped out the broken down catalyst material in the few months I have been hearing it because I know it's gonna be a hell of a job to get the cat off from the j-pipe.