Well the parents are gone for the weekend so it looks like its car weekend and do stuff they will never know about ;)

I'm thinking of jacking the car up and removing the cat then gutting her. But got tons of questions :D First, how easy is this thing gonna be to take off?? I'm betting a huge bitch right? Its not welded on just bolts right???

Second question, how exactly do you gut a cat? Just get a metal pole or something and smash the crap outta the inside??

Thirdly, will I get a CEL from a gutted cat, or is that only for a test pipe?

Fourthly, is there even any point for me to do this, or am I just wasting my time?

Haha, I think thats it, thanks!

I would seriously consider replacing the cat with a test pipe instead. Awhile ago I gutted my cat and I was not really happy with the results. I had to gut my cat cause it was clogged up and my car would stall out every now and then.

Not too long after that I went and had a local muffler shop make me a 2.5 inch diameter, 16.25 inch long pipe, with rotating flanges. I installed my test pipe and really noticed the difference. The test pipe flows much better and smoother than just a gutted cat. The gutted cat leaves an empty chamber where exhaust gasses have to get forced out of. The straight pipe keeps the exhaust flow smooth.

The only bad thing about having a test pipe is the noise. Your car will be louder (more sportier) and it will not sound as good. You will hear more high pitched noises that the cat would normally block out. You can fix this by replacing the stock resonator in the exhaust system with a better / longer one. You will be able to find these at almost any muffler shop.

You will get a CEL if you do not have a cat.... so you can fool the ecu into thinking that the cat does exist and is working properly. The rear O2 sensor does the checking for the ecu on whether or not the cat is working right. O2 sensors in our cars output a signal that ranges from 0 volts to 1.00 volts. The typical values for the rear O2 sensor with a good cat range from 0 volts to 0.44 volts. That will make the ecu happy. So, you simply find the rear O2 signal wire (under the drivers seat) on the rear O2 sensor harness and put a 1/4 watt 100k ohm resistor on the signal wire. This will drop the voltage down to the right range. Please check on the 100k ohm value though, I am typing this from memory and I have not done this recently. I had this mod done to my car a long time ago.

I would not waste my time gutting the cat..... get a straight pipe.

-Jared
96 GS
Melbourne, FL

I gutted my cat a little while back and I am happy with the results for a FREE mod. I definitly felt a bit of a gain and I liked the difference it made in my exhaust note. I have a GST muffler so it wasn't too loud to begin with and gutting the cat just made it a bit louder.

Here is the link with the Radio Shack part number and some more info.

http://forums.2gnt.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=5983&forum=DCForumID25

Chad

True that gutting the cat is free, but I only paid $20 for the pipe and I liked it better.... way more than $20 better if you know what I mean. Just something to consider.

-Jared
96 GS
Melbourne, FL

Is a test pipe just straight pipe, if not, what is it????

Yeah a test pipe is just a straight pipe with flanges on it.

but my question is ... How do you hang a test pipe?....cuz the hangers are on the cat...

Chad

Yup, a test pipe is basically just a straight pipe with flanges on each end.


As for 97 ESi, it is a pain in the behind to remove the cat-converter. The bolts are usually all rusted up, and will more than likely, need to be cut off. Gutting the cat itself is pretty easy, just time consuming. You just take a heavy steel bar and just keep smashing on it until the catalyst honeycomb inside brakes up. It will take a while. Oh, and definitely wear some sort of nose filter and work in a well ventilated area. Breathing in catalyst dust is a no no.

For right now I have the gutted cat, but I will probably go with a straight pipe soon. The gutted cat does give the exhaust a slightly louder rumble.

not recommeded.

y not??

I did mine back in January before my engine blew up, and enjoyed the different tone it gave. The only bitch is getting all of that stock shit taken off, you'll hafta heat it up with a torch (and believe me, be careful if you're leaking oil :) )

Now, I don't even have a cat, or a test pipe wiht my custom exhaust.



Jon

1997 Eclipse RS

14.21@101mph 10/4/02

MODS: 8.8:1 JE Pistons / Eagle rods / Stage 1 Hahn turbocharger / Melling Oil Pump / Autometer 5" tach / 4 JL 12" W0 subwoofers / Clarion 230w amp / short shifter mod / GReddy EVO exhaust / custom 2 1/2" downpipe / no cat con / CM Stage 1 / 30lb Mustang injectors / TurboXS MBC / 1G SMIC / Eibach Sportline springs / KYB GR-2 struts / GReddy 52mm EGT / A'PEXi Super AFC

reasons not to gut cat:
1. it's illegal
2. take a cut in low end torque
3. throws the Cel "Catalyst inefficiency"
4. just try and get inspected without it......good luck if they have a smog detector

reasons to gut cat:
1. it's free
2. nice high end power
3. better exhaust note

just weigh em out, being a 4 cylinder you're still not going to put out as much smog as a V8, buuuut, the popos dont care, admittedly mine's gutted so hehe, do whatchya wish

Yeah, just the other day I got my test pipe installed. I had a Magnaflow mufler on it before, and it sounded not too bad, but now it is pretty loud, which i like. The only problem i am having is that it makes a weird vibrating sound from 4,000 to redline. I noticed that the cat had brackets on it to mount to the car, where as the test pipe does not. Anybody got any ideas what this could be and how I could fix it? Thanks.

Rob Bain
95 Talon ESi

Magnaflow muffler, UDP, IceMan CAI, Test pipe

Are you guys getting your test pipes from www.testpipe.com ? I want one but I can't stand a rattle exhuast system. And what size are u guys getting. All I got right now is a GS-T muffler.