a few months ago i was having serious power problems with my 87 N\A, and we discovered the cats were clogged. we replaced them, and the proble mwent away, but today i was driving and i got a weird noise above 5000 rpm like there was sand going through the engine, and when i stoped and looked under the hood, the exaust manifold was glowing, so i looked under the car and the whole exaust system was glowing red and all the ice under the car was melted. i have no idea what could be wrong, every time someone has a cat problem everyone says it must be cloged, but these are brand new. im stumped help mucho apreciated.

 

what kind of cats are they? if they arent made for rotary applications, the heat genereated by our engines can melt cats made for normal piston cars. what happens is that the exhaust is so hot from out engines, it melts the surrounding insulations around the cat material and causes that catalyst inside the converter housing to shake and bounce inside cousing it to crumble and clog . Bonez makes a good highflow cat for rotary applications.

 

Is your air pump working/hooked up?

 

that was supposed to say there is a noise like there is sand going through the engine not there is sand going through the engine, and i will check air pump, but i dont inderstand how that would affect it

 

forget cats runa striaght pipe, unless u have emissions inspections

 

http://www.catalyticonverters.com/MZRX746898692.html this is the link to the cats that i put on, they say they are for the car so i think they should have been able to take the heat i dunno, the reason i went with this system is because it uses one less cat and cost the same as one of the cats regularly does