Installed ebay full exhaust system, run a cat or test pipe?

[Mike-97 GS]

I bought a full exhaust system for my car and I ran into many snags during the install with things not fitting up properly. I'm now faced with the dilemma of having to buy a new cat or buy one of those cat to resonator converters :

Resonator Converter Cat Eclipse 1995 1996 1997 1999 NT | eBay

My old cat is completely rusted to the old system and there's no way its coming off. I can chop the bolts off, but I don't want to put an old worn out cat on my new system. It's bad enough I already have to replace both 02 sensors which is gonna set me back $84. What do you guys think I should do? My only concern with the converter or test pipe listed above is that the exhaust will be too loud and make me a cop magnet. I have a 3" to 4" n1 style setup.

 

[bryanwheat]

If you have to get the car inspected than definitely run a cat. You can get a cheap cat from rockauto.com in the universal section for like 40 bucks.

 

[Mike-97 GS]

If you have to get the car inspected than definitely run a cat. You can get a cheap cat from rockauto.com in the universal section for like 40 bucks.

I can't weld or afford to have someone weld flanges on to a universal cat for me.

 

[bryanwheat]

I can't weld or afford to have someone weld flanges on to a universal cat for me.

So the answer that you want to hear is to buy a test pipe than. I am not sure what you are looking for here. If you want the car to pass inspection than put a cat on it. If you want it to fail and not be able to be registered than just throw a test pipe in there. Lastly, if you can afford to complete the project properly than it probably would of been a good idea to wait until you have the money to do so and leave the stock exhaust on there.

 

[Terrancep7]

Buy a cat or test pipe your choice you will neither gain or lose much with either. As for the 2 o2 sensors you only need one just leave the downstream off but plugged into the connector under your seat and put a plug in the exhaust. It Won't throw any codes this way. And the cat or test pipe which ever you choose is like 32 dollars off ebay that's how much mine was atleast.

 

[Mike-97 GS]

I got a direct bolt in replacement cat just so I could get the car running again for school. Probably have some leaks that I gotta fix and there's a nasty burning smell coming from the header, but it's probably just the JB weld on the cap I had to use to seal a hole on the header used for something with california emissions mixed with some muffler weld crap on the header joint and the new cat and pipes being broken in. Hopefully the smell goes away soon but for now I have to drive with the windows open.

 

[bryanwheat]

Watch out with the jb weld on the exhaust. I have in the past seen it catch on fire when used on exhaust.

 

[Mike-97 GS]

Watch out with the jb weld on the exhaust. I have in the past seen it catch on fire when used on exhaust.

Yea...they really shouldn't advertise it can withstand the temperature it claims on the box when it fails on first start up of my car. I scraped most of it off though so I don't think I'll have an issue.

 

[DEADKITTY]

Why not gut a cat converter and have the benefits of a test pipe with the looks of a cat?

 

[Joethefallen23]

Why not gut a cat converter and have the benefits of a test pipe with the looks of a cat?

A gutted cat is about the worst thing you can do. It creates an empty chamber about 3 times the size of the exhaust pipe where the exhaust gases will expand and slow down. The gases don't particularly enjoy compressing back down to the smaller exhaust pipe. Outgoing gases from the engine collide with the slow moving gases causing tons of turbulence and backpressure.

At that point, you could just buy a testpipe with a cat shell on the outside. Worked good in my case. Passed visual every time and passed OBD2 scans with an o2 simulator.