can a clogged up catalitic make my 88 gtu quit running completely?

 

If you mean not even start, I doubt it. I would think that even the worse clog would allow the engine to at least start. It would only run until it couldn't overcome the back pressure. You could open up the exhaust up stream (even just a little) to verify.

 

if it was completely clogged than it would, but its unlikely its that bad. you can check it by taking out the o2 sensor and cranking it.

mike

 

no i doubt it would completely stop running, youd lose HP, and if you have a header on, it'd probably be bright orange/red.