Does size really matter...[exhaust piping vs smog test]

[TurBoGs-T]

My ? is does Exhaust size really matter when doing emissions testing??? I failed my test the other day. I thought i had the stock system on there but i don't know what the heck the previous owner did. Looks like he has a 3inch dp eliminator and stock catback. Anyway if i just put on a full 3inch exhaust with the cat.conv. will that still pass emissions or is 3inch automatic fail due to size???

 

[Herbal Essences]

Size of the pipe shouldnt matter as long as you still have the stock cat. Intresting, anymore details of your cars mods?

 

[TurBoGs-T]

I have to have the stock cat on there??? i can't do a 3inch system with the stock cat. I can't just put a 3 inch cat on there and pass???

 

[Herbal Essences]

I dont think so, I would reccommend putting a stock exhaust on for the test. To me the aftermarket cat seems to be the problem.

 

[TurBoGs-T]

. I don't have one at all.

 

[Herbal Essences]

I would look into buying one if I were you, or find a place that is "easier" on cars.

 

[doug]

The catalytic converter does not have to be "stock" in order to pass emissions. Yes, a 3" high-flow cat should be just fine.

 

[TurBoGs-T]

Originally posted by doug
The catalytic converter does not have to be "stock" in order to pass emissions. Yes, a 3" high-flow cat should be just fine.

That was like music to my ears!!!!! Thanks

 

[Herbal Essences]

Originally posted by doug
The catalytic converter does not have to be "stock" in order to pass emissions. Yes, a 3" high-flow cat should be just fine.

I would have thought that too, but he did fail emissions with is.

 

[doug]

But he went on to state that he doesn't even have a cat at all:

Originally posted by TurBoGs-T
. I don't have one at all.

 

[Herbal Essences]

Do you need a cat in maryland?

 

[TurBoGs-T]

I'm almost sure you do. They don't look for one under the car but the test can read if you have one or not.

 

[Herbal Essences]

Well, if you dont have a cat, that is probably why you failed emissions.

 

[jdmawd]

Originally posted by TurBoGs-T
My ? is does Exhaust size really matter when doing emissions testing??? I failed my test the other day. I thought i had the stock system on there but i don't know what the heck the previous owner did. Looks like he has a 3inch dp eliminator and stock catback. Anyway if i just put on a full 3inch exhaust with the cat.conv. will that still pass emissions or is 3inch automatic fail due to size???

A week after I installed my thermal cat back I had to have my car emission tested. At that point I still had a stock down pipe and cat. the car passed. However the awd treadmill was broke. I hope its broke again because I have to now have a 3" converted welded in to pass emissions next month

 

[TurBoGs-T]

Originally posted by Herbal Essences
Well, if you dont have a cat, that is probably why you failed emissions.

Lol. I already knew that.
My ? was is would a 3inch system with a cat pass.

 

[Herbal Essences]

Originally posted by TurBoGs-T
Lol. I already knew that.
My ? was is would a 3inch system with a cat pass.

Ah, I gotcha now. Yeah you should be able to pass emissions.

 

[92TALONAWD]

I passed last time with a 3" downpipe, 3" high flow cat, and 3" cat back. So you should be OK. As long as the emissions are all with in spec.

 

[TurBoGs-T]

Originally posted by 92TALONAWD
I passed last time with a 3" downpipe, 3" high flow cat, and 3" cat back. So you should be OK. As long as the emissions are all with in spec.

Great now i have an excuse to buy my 3 inch system. plus if i spend more than $450 i automatically pass.

 

[midnght]

Yes, i have a 3 in system and passed MD inspection. Just make sure your emissions are good. A true 3 inch all the way with a cat. is good to pass. I just had to lean the piss out of my car and take it on an ITALIAN TUNEUP

 

[doug]

Originally posted by TurBoGs-T
now i have an excuse to buy my 3 inch system.

If you're only going as far as a Frank Jr. turbo as is listed in your profile wish list, a 2.5" system would be better suited for your application.