My indie has officially given up on my car. A little background- it was running great. I drove it 1200 miles to the Parade in June without a hitch. It ran fine for 3 months afterwards. I went to start it one afternoon and it would not hold an idle, coughing, backfiring and every other kind of noise. Check the codes and said misfire on 4,5 & 6. Tried to start again and it ran fine. A couple of weeks later it did the same thing only this time misfire on 1,2 & 3. Had it towed in and replaced MAF, plugs and O2's. Then my mechanic discovered clogged cats that had actually exploded inside. Replaced the cats and the MAF again. No luck. Checked intake for leaks all good. Anybody have thoughts on what this could be?