Gutted cat vs. Test pipe/mid pipe/resonated mid pipe/ etc.

[Nc MSP]

going to be doing a slight exhaust overhaul soon and wanted to know the pros and cons of all these, like dyno gains/sounds and all that good stuff. keep in mind i have to pass emissions and i do have spark plug non foulers for my o2 sensor to pass in case which ever option causes me to fail.

 

[MSPBETZ]

i would also like to know this....

 

[Nc MSP]

seems like no one has a good logical answer...

 

[fatti03msp]

When i was in PA even if i didnt have a check engine light they still checked for a cat. Not sure how your inspections are like though.

It will be a lil louder but not annoying or raspy. Will help with turbo spool up too, cats are very restrictive.

Cats are worth decent money so gutting it is kind of like throwing money away but at the same time you need to spend money on a mide pipe so its your call.

MSP has two cats and i think each will fetch you 40-60 bucks depending on what the market is like.

exact gains i have no clue

 

[funkalicious21]

I've have been going through this scenario through my mind for awhile. Since California is one of the hardest states to pass emission test it makes it hard to decide on what kind of overhaul I'd want to do. If I had not to worry about emissions i would have gone w/ a straight pipe, pure gain w/o restriction.

gutting cats should make things a little louder. Not really sure how much more louder. There's a difference in sound when comparing n/a to turbo exhaust setup. Supposedly the turbo make the exhaust quieter. (correct me if i'm wrong). Cats do restrict flow and I'd get cats if you're worried about cops. No cats = smelly fumes and possible black smoke . It's like asking for a ticket here in Cali.

Since I'm in the same boat this is what I'm doing: 2 bungs (one wideband and one down stream o2 or exhaust temp gauge or non-fouler), 3" pipping, and 2 cats. It's pricey, but it's the piece of mind of not having to worry about the exhaust being too loud and not having to worry about the cops being on your ass.


Gotta pay to play....

 

[fatti03msp]

ya turbos do act kind of like a muffle keeping down the noise.

 

[_Chris]

Turbos do help keep the sound down a bit. But then it depends on the type of muffler you put on it on how loud its going to be. A gutted cat would be quieter than a straight pipe would be. Depending on the size of exhaust you go with. The larger the pipe the louder its going to be. Its going to be hard to say this set up is going to be better over another. As far as a hp gain over over each set up. I don't think you will feel a difference.