bkelley

I really want a MAC pro chamber, but I need to be able to pass a smog test. Was just wondering what the best sound/performance option would be that would still pass smog? I like the raspier sounding exhausts like Mac and Flowmaster. Was looking at the Mac catback system from American Muscle.

Aereon

you should pass smog with any catback with the stock midpipes. If you are in California it is a bit iffier, if you get pulled for visual you need to explain why your catback is different from stock. Also catted midpipes can pass in california, but just barely, I barely passed by .04 ppm's.

Replacing non broken cats in cali are illegal in cali, also the refs will check for 4 cats in an h config.

bkelley

Yeah, I was actually thinking about just doing axle back since the GTs are already setup with a pretty good exhaust system. Get some Borla S-Type mufflers and some nice 2.5" or 3" chrome tips.

BLKSTANGER

Yep our hand are tied for the most part. That is unless you want to swap exhaust every time you need to get it smogged. CAT back is about all that you can do.

LilRoush

Some people get too hung up on exhaust modification. There are dozens of other ways to make power. I'm only running a cat back and am just fine with it. In any state (checked or not), it's illegal to remove the pollution control.

Rockwell28

True!!!!

Bay_Area_Boy

Why would one need to explain the additon of a catback? should i not get a cat back because of cali laws?

mineralpony

I'm not sure what your state restrictions are but see if you can get cats on a prochamber (pretty hard) and go with a chambered muffler to keep it quieter than the straight through ones.

Aereon

Because carb laws are stupid, from what a few sfpd friends of mine have said, ANY modification to the stock oem exhaust that makes it louder is technically illegal. However, unless it's obnoxiously loud most chp/cops won't bother you for it, also read that as you not being a tool while on the road. The downside to that is, if you get a chippy or someone wanting to ruin your day and you get sent to a ref, you better explain why there is anything other than oem exhaust coming from the engine. I've heard of them taking the headers off a car in order to check for the carb stamp cause they couldn't see it from underneath or on top.

[rant]The way I see it is, if it passes the sniffer and is not obnoxiously loud, I don't see the reason why our tax dollars are going towards someone that does nothing but looks to see if you have aftermarket parts that has not spent the time/money to go through carb certification. Would like to see some of that cash go towards school or repaving the roads, was so happy a few months back with the budget crisis and carb closing down for awhile, only to have them reopen and lower the threshold for smog.
[/rant]

Phaxtor

+1 I completely agree with said rant.