I decided to put everything back together for now after I removed all the broken cat pieces. Once I got it all back together and cranked it up there is considerable smoke that wasn't there before. Some of it appears to be coming off of random parts, I believe, where I sprayed liquid wrench. The other area I see smoking is where the cat connects to the header. Did I just not tighten everything up enough?

 

If you used lubricants to get stuff free, then the smoking is normal, just wait for it to burn off.

Each of the two places where the cat meets the other pipes there is a graphite gasket to seal it. Thin gasket in the front is often hard to hold in place, though I think the OEM cat has a lip that it can sit on. The rear is more of a cone shaped gasket. Both are crushable on purpose, and technically not supposed to be re-used, although it's possible that you can re-use without leaking. If one leaks though, replace it. (orderable from most parts stores)

You will also smoke a bit more in general, since there isn't a cat cleaning our relatively filthy exhaust. Like if you premix, you should now be able to see a faint blue haze from the tailpipe when at full throttle.

I'd recommend resetting your fuel trims as well, since your engine flow characteristics changed.

 

Absolutely. Would have saved me quite a lot of time, effort, and a few cut/bruised knuckles.

 

Riwwp how do I reset the fuel trim?

 

Either the 20-brake-pedal-stomp method or pulling the negative battery cable for a minute or so. The 2nd does everything that the first does, but also resets more, including stereo presets, etc...

 

Oh okay thanks

 

Well Everything is put back together and I just took her out for a test spin. She's running really nice and after about 15 minutes of driving I pulled over and noticed the smoke is significantly less than when I first started up after reinstalling the Cat. I'm sure after a few more drives all of that liquid wrench (I used alot) will burn off.

I will be replacing the CAT and in the meantime try to drive the car as little as possible to minimize any possible damage.

 

No worries about damage if it's just a gutted cat. Seriously. Having a cat does more engine damage than not having one If the cat is functional, at least the damage it does is very minor. If it's clogged, the damage gets quite severe. Freeing up power, exhaust flow, and reducing heat buildup in the header. Not a bad thing at all. Though your significant other's nose may disagree

 

I am looking at purchasing an upgraded cat and exhaust header. I will do the muffler too but those tend to be more expensive and I'll have to wait a bit. Do you have any general guidelines on shopping for new cat converters and/or exhaust headers? Right now I'm looking at a Racing Beat cat and a magnaflow cat. Exhaust headers seem pretty standard across the board so I assume spending more on that won't make much of a difference?

**Edit: I'm aware of the potential HP gains (or lack there of). My system is old and my cat is broken as indicated in this thread. I'm using this as an opportunity to upgrade and get a little better sound out of it and maybe a small power gain if possible.

 

See the 2nd link in my sig. A section for each of the different exhaust parts within the first 3 posts.

 

You might want to search up on the forums. There is a lot of info at your disposal, you just gotta find it.

 

So I'll start with the exhaust header and work my way back. Good information. Thanks alot.

 

I now have over 10,000 miles on a metallic-substrate $100 Magnaflow Cat, Search Results for magnaflow 59959 - SummitRacing.com It comes is other diameters as well.

It's survived about every NA abuse thrown at it short of full blown track days. No melting evident, nor CEL or NOx stink, though I have no idea if it would pass a sniffer test.

 

Thanks for the info. I'm debating between a magnaflow and a BHR midpipe at this point.

 

Get a midpipe, make more power and no worries about cat failure. The only downsides are if your state has emissions testing and your exhaust will stink. Oh and you can shoot flames does that count as a benefit?

 

Girls no likey stink.

 

True that! But just turn your a/c on and put the air on recycle, and pray if someone opens the door the wind hits the exhaust at the right angle!

 

Easy answer:
Don't drive slow enough for your exhaust to catch the girl in the passenger seat