This is probably a no brainer. But since its -20 outside, I'll take advice over troubleshooting. Today my '93 88 ran all good a couple times. Then I got in to go again, ran rough. got worse as I drove sputtering, backfiring, no power. Oh the way home, I noticed sparks (yes sparks) coming out of the tailpipe. So my conclusion would be the c.c. had a fatal meltdown. Thoughts?

Could be. Remove the O2 sensor and see if it drives better.

Do you have a generous muffler shop nearby? Maybe they could punch a hole in front and behind the cat to see if there'* any airflow

Unfortunately, no. I live in the sticks and I am going to have to call and even see who does exhaust. Although I can disco the 02 sensor, I cannot see that causing sparks to blow out the tailpipe. Agreed?

you take it out to see if the added exhaust flow helps.

I took it out and there was not material left inside. So I figured its broke up and clogged the muffler. replace the muffler, still runs like crap

did you replace the cat?check the whole pipe for clogs?

Did not replace the cat. Its straight through. Took all the exhaust down checked, not a darn thing in that pipe

By runs like crap, you mean no power?

Did you try to road test the vehicle with the exhaust disconnected, to eliminate a back flow problem?

If you did, and it runs like crap, then back to basics.....if driven with a misfire, that misfire could have taken out the cat.....

Check that f/p reg hose for fuel....try driving with the MAF disconnected......check fuel pressure, and spark on all cylinders with a spark tester......

Scanned for codes?

losing coolant?

The car would not scan at all. So I am going to do spark test tomorrow, just picked up the tool. MAF is new, so I don't think that'* the issue. Hoping its a coil pack. Fingers crossed