i had just gotten of work and was pulling onto the the highway, and needed to get up to speed a little bit quicker than usual, which is fine because i like doing it, and my car definetly has the oompf to do the job. but right as it shifted down one gear i hear a big boom, followed by a loud scraping noise, and then followed by the sound of a dragster taking off. the cat blew off the Y pipe. the hanger broke, and the intermediate pipe has now been blown to pieces. what the heck happened?! i dont understand, i dont even have a plugged up cat. i removed all the interiors of the cat, and then welded the top of it back together. still looks legal. so what my question is, how could this have happened? and im looking at T.E.S headers and y pipe, catco cat, and american thunder catback. is this a hard set up to install? how long did it take you? and will i have issues with it scraping on the ground like my old set up? its really ticked me off that this happened, because now i have to ride the bus everywhere until i get this fixed. thanks for all your guys help.

 

The setup your looking at is exactly what i have on my 91 RS right now. As for the headers they were very easy to install on my L03, different engines though it might be different for you. The only time my exhaust every scrapes is at school if i take a high speed bump strait on, other than that its fine.

 

unburnt fuel tends to gather in a gutted cat... then blow up. I've seen it happen to cats and mufflers. Pretty cool unless youre the one driving...

 

man, i wish i would have known that before i did it. i just would have bought a new cat, instead of a whole new exhuast. which should be here tomorrow. at least now i have some good advice to give to my buddys who were pleased with the way mine turnew out. haha.

 

i'd be more worried about how the car is running... does the exhaust smell rich or is it smoking black at all?

 

yes, the car has been running rich. i have been trying to figure out why. i timed it, replaced the cap, rotor, plugs, and wires. but nothing. my check engine light has been on, and i havent been able to figure that one out either, but i dont have a code reader. i havent found anywhere local to get it read either. any suggestions? i also noticed when i was looking underneath it when the cat exploded that the small line running to the cat had been cut for some reason. must've been the previous owner. i cant figure out why its running rich, or why the check engine light is on. any suggestions?

 

you don't need a code reader...just grab a paperclip and follow this how-to

https://www.thirdgen.org/service-eng...ht-error-codes

i'd be willing to bet your o2 is shot...

 

Or go to Autozone. They read the code for free.