I have the a bonez cat but I also gutted my two precats I have a 1987 N/A, it's a sport doesn't seem like that would make a difference in this instance. I have the stock exhaust as well. Here's the problem the car is extremely loud, (well not as bad anymore I'll explain later.) I've been living with it because i haven't had a chance to drive the car , I've been going up to no. cali from so.cali alot. The car backfires a lot when I do a quick 1-2 shift or down shift at all. Recently I started doing all the serious fluid and etc. changes. New diff, tranny, clutch, brake, etc. Well I got to the spark plugs and found they were caked in black soot and very oily, now I've put new spark plugs in and the sound has cut down to about half and the backfiring is at a minimal. Also, it seems I have an exhaust leak but I've changed all the gaskets, bolts, and washers to no avail. Anyways after everything is said and done I was wondering if this is what are cars should sound like,(because they are rotaries)? Or is my car seriouscly fouled up somewhere.

P.S. I didn't gut my precats because I wanted my car louder I did it because they were shot and the local dealership wants nearly $1000 for a set.

Thanks for reading this and any help you can provide.

Mark Moros

 

I have the bones racepipe, so I have no precats or cats, and I have the stock catback...my car isn't very loud at all. Its kinda loud at wide open throttle but no VERY loud by any means. It hums at lower RPM's and gets more aggressive at higher RPM's, but it always sounds smooth. When i first put on my Bonez over a year ago, I screwed up and ended up with an exhaust leak. It made my car VERY loud and crappy sounding. A week later I realized I had an exhaust leak and fixed it. So maybe you still have an exhaust leak, or maybe your mufflers are shot.

 

I can almost garuntee that your gutted cats are the problem, I have found that on every car that I had that the cats were gutted that it sounded like there was a leak. I replaced gaskets and everything. One of the cars I ended up putting a straight pipe in place of the hollow cats and the sound went away. For some reason I find the cats 'buzz' and sound like a leak when they are gutted.