I live in an non-emissions state. I know this for a fact. My friend took off his cat converter, and welded a straight pipe to his exhaust, and it sounds soooo much better! and louder too! I want to get Dynomax Super Turbo Exhaust system, and I want to run a straight pipe as well, but here's the problem. My old man is CONVINCED that this is an emission testing state, and won't let me do it. Is there a way to gut my cat, or do something to it that will have the same effect as a straight pipe, but with the 'Appearance' of a cat converter. Any suggestions?

 

How long has your dad lived in MI? Anyway, you take the cat off and run a pipe through it so its a straight pipe with the cat welded or whatever around it.

 

Hey, thanks, I'll try that. He's lived in MI since like the 70s, and he STILL thinks we're in emissions testing.

 

yeah strait pipe the cat. and put the pipe threw the gutted cat and then weld it , is actually a great idea. Puttin a pipe makes it sound way better and flows . Gutted Cat = Doesnt flow good, and causes lots of turbulence and can cause affects of performance. I know, and it also gives a really cruddy voice for exhaust when you gut it .

 

Nick is right, most guys that leave a hollow cat or just stuff something through the cat material actually get a lot more turbulence and less flow than a straight pipe. The right way to do it would be to cut the cat open, and run a straight pipe through it, and re-weld it shut.

However, there is another alternative that might work even better all the way around. If you still have the stock cat on your car, it is actually '70's technology, and has about 20 years worth of crud built up in it.

The new cat converters are much smaller, lighter, and MUCH higher flow than the originals. The high flow cats definately change the sound and pick up power, and I have seen dyno tests where a straight pipe vs a high flow cat gained less than 1 HP on a 400 HP car!

...just a throught. Good luck.

 

Ask him if you can see the results of his last emissions test.

 

Michigan is not an emissions state, but if you've got a V6 I say leave the exhaust alone. You're not going to sound any cooler, let alone be any faster, in a V6 with a cat missing and a catback. Your car will sound like crap. Don't believe me? Come to Ypsilanti and Ann Arbor and take a listen for yourself.

:lala:

 

Your old man is smarter than you think. Theyre reinstating the tests in a few years, and 1991 will be the cutoff date. So not only would you sound like crap, but you also wouldnt pass the test.

 

A test is one thing, federal law is another. I don't get tested for grand theft every year, but that doesn't mean it's legal to steal a car.


...that said, I don't care what you do, but several people feel that the cat makes the exhaust sound better, and isn't worth the minimal loss of power.

 

Having a cat is a federal law anyway, if you have a straight pipe and someone wants to be an a-hole you can get a fine. Just make it look like you have one