Hey everyone well today i was talking with my friend about exhaust he said if i want more hp and a louder sounding car that i should remove the catalytic converter he said its illegal though. i was wondering if anyone here has done it and how much of a difference is it sound and performance, i have magnaflow. so i was just wondering if i should do it or stay regular.
thanks

 

I just opened the same forum yesterday and noone repsonded, so i don't think they know exactly. I have stock manifolds and SLP Dual/Dual and noone knows, i'm curious too. Also, if anyone knows how much a shop should charge to do this.

 

my friend told me around 40 dollars.

 

2-3 HP.....Much louder...better IMO.

 

very little power, but a lot louder. As for any of us doing it, I'm not so sure anyone with an f-body would consider doing something illegal. . .
Actually, every sig you see with ORY in it means that person doesn't have cats, there are tons of us that don't have cats. I, uhhh, think we're all track only cars though. . .

 

You live in california? Just forget about it right now.

 

if you plan on doing long tube's later, its not worth the effort to remove them now. Just get an ORY when you do the longtubes.

 

Whats up to the two guys interested in the mod. I just completed it about 2 weeks ago and I will say that it sounds pretty bad ***. I knew ahead of time it would because I did it on another v8 i had a while back. As far as cost...you will need to replace the two gaskets that go b/w the y pipe and header flanges but those are 20 bucks at any chevy dealer. Whatever you do, don't make my mistake! Lube the heal out of those nuts so that you don't break the six bolts holding the y pipe to the headers. It's fixable but will require about 4 more hours of you time and it sucked bad. I've heard the chemical pb blaster is extremely effective. Once well lubricated the nuts should come off. Let them soak at least 2 to 3 times at 30 minutes per soaking (You can't be to heavy with the penetrating oil...the more the better). When you get the 6 nuts off...god forbid you break one, disconnect the U Clamp that holds the end of the y pipe to i pipe. When the clamp is lose, grab the two heads of the y and yank towards the front of the car...it will slide right out. Once the y pipe is off, take a crow bar and a hammer and go to town on the inside of that cat until its completly out (takes about 10-15 min per cat. On the passenger side cat, you will have to cut it and reweld because their is a bend before the cat so there is no way to know it out. Just mark it up so it can be welded back in the same way (5 bucks at a muffler shop for welds). Once your done with that...get back under your car and you will have to use both hands and feet to line that pipe up with the header flanges. A friend is a great tool when lining this back up. Once in place, retorque your flange nuts once again using anti-seeze chemical and connect the end of the ypipe back to the i pipe. Your done! Crank it up and listen to the bitch roar. You will crack a smile when it cranks trust me. You will also feel the difference in power from a dig also until your SES light comes on and requires you to either get the code deleted or buy o2 sims. Once that light is on for about 25 miles, you will see why you need the sims because your timing will retard for (preventative engine damage) dont worry you car will be fine just sluggish until you reset the pcm or get the sims. (Just buy the damn sims). I just got mine of ls1tech's classifieds for 45 shipped. Their all over this site. So after all said and done, you've got (20 for gaskets + 5 for rewelds and 45 for o2 sims equalling = 70 bucks. Oh yeah and about 2-3 hours of labor . In my opinion this is a great mod for someone who wants the benefits of sound and mild power without spending the 500-600 for aftermarket headers and an offroad y pipe or for someone with clogged cats. Let me know if you have any questions about the mod because I can definetly help ya'll out...Josh.

 

thanks alot man that is very helpful

 

Totally not worth it at all.

Yes it will make your car louder, but worse sounding as well. If you want louder simply run a different catback or dual exhaust that has less mufflling.

A SLP Loud Mouth or GMMG or TSP Rumbler X duals.

As for bhp - yes stock CATS are restrictive, but the exhaust is a whole system you need to do the whole thing to get any real gains. So simply removing the stock cats won't suddenly turn your car into a fire breathing street warrior.

Also it is a federal offense to remove CATS. However many states don't actually check.

CA is different though and you will need to pass a visual test as a rule, meaning they will look under the car. ODBII test is where they plug a scan tool into your cars PCM. Without CATS it will throw a code.

Fake cats and deleting of codes via tuning can work to pass such things. But again in CA it is unlikely to work.

Also if you have to pass a sniffer test there is no way to do it without CATS.

Essentially if you are in CA forget about building a modded car the same as everyone else.

Get a aftermarket catback. And leave the rest of the exhuast alone, unless you find a way of really upping the HP.

Pulleys, intake manifold, TB, lid, heads, mild cam are the way to go. Non CA guys can have wild cam and LT headers and make a decent chunk more HP.

Large displacement motor or a supercharger is really you only option for BIG power.

You then will need shortie headers (CARB approved for 100% legal) and high floe CATS (probably metal matrix ones).

In short:

LEAVE THE CATS BE!

 

The man above speaks the absolute truth.

 

Thanks Connexion2005, I'm gonna do it tomorrow i think. Thanks for the help, and oh yeah, those bolt on the driver side are rusted solid and they suck. Also, I'm working with only two floor jacks, So don't know how easy that y-pipe is gonna come loose but i can get it out, but will i get it back in without heating it? Oh yeah, AND WHAT IS THE COKE CAN THING ON TH EPASSENGER SIDE UP BY THE MANIFOLD?

 

More backfire, really loudened up my Magnaflow with my cam install, and did help alot with the flow. Bad thing, alot more gas fumes.

 

take the cats off and watch all the heads turning as your mean sounding ls1 tears up the road.

 

Yeah, sounds excellent, i know, I yanked mine when I put LT's on, but with California's "drag-net" campaign they're running now, you'll only draw attention to yourself, they'll write you a fix-it ticket for sound emissions (they don't even have to physically test it, just by judgement) and have you go to the CHP and have it inspected to see if it's street legal, that's why they find the big no no's, and write you tickets up the *** for every little thing that doesn't have a CARB # on it.

 

your right about that. its only a matter of time before every state is like that thats why i'm gonna enjoy it while i can

 

**** it,and remove the cats

 

if your in cali dont do it your going to regret it when you cant pass smog,and get fix it tickets, i know i use to live in cali with there stupid smog ****, thank god i am in texas now

 

Basically, california is all dreams and bullshit...go to texas or florida and you'll be happier then ever, with your badass car