used seafoam (3/4 oil, /1/4 in gas) next day car runs horrible, under 3k it "bucks" then drives fine at higher speed, however after 1 mile it starts to smoke, finally i looked when it was dark out and noticed the cat is glowing red hot! could my cat be all of a sudden clogged, and would this cause the bad running? also for budget sake would gutting the cat cause more problems than it would resolve here? (also no emissions in fl)

 

That's the problem with seafoam and related products. It works great but you have a high chance of damaging something. I've seen a lot of bent valves due to seafoam breaking up the rock hard carbon deposits and shooting them out the exhaust valves only to be caught and bent.

Chances are, the front of the cat is clogged. You can certainly gut it but it would not be federally or locally legal. Even though Florida is an non emissions requirements state, it still requires stock exhaust and you can be ticketed for having just an aftermarket muffler that's louder than stock technically. Will they pull you over for a gutted cat? Not likely.

You will have to attend to the cause of the catalytic converter issue. I would say check the cat out, if it's melted, gut it. Then test the car and see if it misfires any longer. If it doesn't, it may have just been the cat got too hot from the seafoam and melted it. If it still misfires, well that's another story =P

 

im just going to wait until my next day of and un bolt the down pipe from the turbos and see if it runs normal again. car only has 106k and one thing i noticed is that there was NO white smoke after putting the seafoam in (all my other cars made my block look like a smoke storm went through.) im just not sure if a gutted cat would pull a code on the car. just another thing to fix on my "new car"....still have to get my massive oil leak looked into.

 

You'll most likely get a code for the converter if you gut it, but it's just an emissions code. No way around that unless you buy a replacement. Most aftermarkets converters will still throw a code. You can get a bolt-in replacement from rockauto.com for about $350 or try your luck with a universal and have an exhaust shop weld it in.

 

humm....i unbolted the cats from the down pipe and started it up, still runs the same (but much louder now lol. i pulled the plugs and one was pretty nasty but overall they weren't too bad, now im leaning towards a bad coil? i tore down the front of the engine today to discover the pcv was fine, next week ill remove the turbos and see if there is any issue at the rear of the motor.

 

At least you know it's not that cat causing it to be backed up like that. So you've got a hard misfire then it seems. A bad enough misfire could certainly cause a red catalytic converter. While you're diagnosing it I would suggest leaving it disconnected (if you can) to prevent further damage.

Have you checked for codes to see if there's a code for which cylinder misfire yet?

You could do it old school and unplug each coil one at a time and see which cylinder does not change the idle when you unplug it. If you've got one nasty plug I would bet that's the cylinder you have an issue with though. The one that was nasty, did it have oil gunk on it? Was it white or black on the electrode?

 

the car engine light does come on when it misfires, but im not able to get it ao a autoparts to have them run the code...almost worth buying the obd2 scanner

 

turns out 3 coils went bad within a few days of each other, replaced them, and its driving great. the cats did not get red hot (glowing) after a trip around the neighborhood.....would the loss of spark in 3 cylinders cause the cats to glow bright red from excess fuel?