should i remove my cats?
- Thread starter gwmcgowa
- Start date
trinity_gt
10 Year Member
The power gain is minimal, the sound quality almost always worsens (IMHO) and depending on where you are, you may have issues later with passing emissions testing. You'll also need MIL eliminators or a tune to shut off the rear O2 sensors to prevent a MIL.
SaleenGT2001
Well-Known Member
sound is much better IMO (as long as you run mufflers) and if you can pass an inspection, i say do it!
My modern car with a x-pipe with mini cats and a Magnapack catback (straight-thru mufflers) gets alot of compliments.
ChillPhatCat
20+ Year Stangneter 
What about weight? It's something to consider. Also, it wont sound bad with the right mufflers. There aren't really any bolt-ons that add tons of power so to say that removing the cats isn't a good idea because you wont gain that much doesn't make much sence. With that argument, the only mods that should be done are power adders and internals.
patman0911
Founding Member
I've been running without them for a while now but I've got mixed feelings about it and am considering welding in some high-flow cats sometime soon.
It sounds mostly good but it does get harsh and blatty right around 2200 RPM (that sound is my economy shift indicator
) and it's kinda loud, like, cringe when I fire it up in the morning while people are still sleeping loud, or, rolling through the neighborhood at 3am trying not to touch the gas pedal loud. It sounds kick-ass at idle and sub-2000 RPM cruise and it sounds glorious from 3000 RPM to redline at WOT but I would like to reign the volume in a little and I feel a little bad not running cats. The state of Alabama may not seem to care about emissions equipment but I thing they're a good thing in general as it's amazing how much cleaner the air is than it was 20 years ago. Mine's not too bad but you can start to smell it if you sit in a drivethru for any length of time and for all the headaches the CARB and federal government have caused for car enthusiasts, auto manufactures and the performance industry, it's really nice to be able to sit in rush hour traffic today with your windows down and not get a headache from all the exhaust fumes.
The factory h-pipes aren't as bad as they look, at least when they're not old and clogged up and as stated before, you're not really gaining a lot by losing them.
It sounds mostly good but it does get harsh and blatty right around 2200 RPM (that sound is my economy shift indicator
) and it's kinda loud, like, cringe when I fire it up in the morning while people are still sleeping loud, or, rolling through the neighborhood at 3am trying not to touch the gas pedal loud. It sounds kick-ass at idle and sub-2000 RPM cruise and it sounds glorious from 3000 RPM to redline at WOT but I would like to reign the volume in a little and I feel a little bad not running cats. The state of Alabama may not seem to care about emissions equipment but I thing they're a good thing in general as it's amazing how much cleaner the air is than it was 20 years ago. Mine's not too bad but you can start to smell it if you sit in a drivethru for any length of time and for all the headaches the CARB and federal government have caused for car enthusiasts, auto manufactures and the performance industry, it's really nice to be able to sit in rush hour traffic today with your windows down and not get a headache from all the exhaust fumes. The factory h-pipes aren't as bad as they look, at least when they're not old and clogged up and as stated before, you're not really gaining a lot by losing them.
trinity_gt
10 Year Member
It does if the cost (or potential cost) of gaining a few HP includes things like having your exhaust rasping during acceleration and popping and crackling every time the throttle is lifted (which might sound cool for about 5 minutes before wearing increasingly thin...), being stopped by police suspicious of the sound and being issued a citation for illegal emissions modifications, failing emissions testing and having to go to the expense and trouble of swapping in the OE pipe (and one had better hope he saved the OE pipe and didn't sell it on eBay...) and so on.
This particular modification carries risks and potential costs disproportionate to the gains than most other mods do. If you live in an area where emissions tests don't happen and think you can live with a raspy, poppy, crackly, unrefined-sounding exhaust then go for it. At the very least though, I'd recommend keeping the factory H-pipe around just in case you grow weary of the sound or an overzealous cop decides that you've committed a felony by willfully removing an emissions control device on your car...
My first exhaust setup was bassani headers, O/R X pipe, and magnaflow regular catback. Sounded like crap IMHO. It was raspy , i couldnt pass inspection and had to pay for a hookup on a sticker, and not to mention the headache i would get from the fumes sitting at a stop light.
My new setup, i had bassani high flow cats welded back in, and changed to magnaflow mangapacks. It sounds soooo much better, it sounds like a nice tuned exhaust, instead of raspy,dumpy sounding. Plus I can easily pass inspection and no more fumes. I'm happy with this setup.
My new setup, i had bassani high flow cats welded back in, and changed to magnaflow mangapacks. It sounds soooo much better, it sounds like a nice tuned exhaust, instead of raspy,dumpy sounding. Plus I can easily pass inspection and no more fumes. I'm happy with this setup.
I've been running without them for a while now but I've got mixed feelings about it and am considering welding in some high-flow cats sometime soon.
It sounds mostly good but it does get harsh and blatty right around 2200 RPM (that sound is my economy shift indicator
The factory h-pipes aren't as bad as they look, at least when they're not old and clogged up and as stated before, you're not really gaining a lot by losing them.
Ok Al Gore LOL.
deftsound
Please ask me how much my supercharger cost
lol what??? 2" exhaust? What are you talking about?
IMHO you gain a good power increase with no cats and it sounds a lot better. I guess if your an old man and you don't like anything moderately loud than you should stay away from a cat-less midpipe, but other than that i say O/R all the way...
Basicly its a matter of opinion if you think it sounds better or not. But as far as power, you definitely see some gains.
deftsound
Please ask me how much my supercharger cost
First of all i highly doubt its a felony. Secondly, ive Never ran cats and ive had 4 mustangs over the past 7 years and not once have i gotten pulled over for being too loud or not having cats. Now if your are running slp 1's and an o/r pipe yea its going to sound like crap but with a decent muffler like flowmaster, mac, borla, bassani it will sound awesome.
And third like i said previously its a matter of opinion whether it sounds better or not. Mine does not sound raspy in the least bit and neither does it sound poppy, crackly or unrefined.
trinity_gt
10 Year Member
I believe that in most instances the Federal Clean Air Act makes the removal/disabling of a catalytic converter a felony and exposes one to a fine of up to $10,000. It's federal law one is breaking when one tampers with otherwise-functional cats on their car.
And for every anecdote of this nature there's one of a guy "harassed" for this very thing.
Again, anecdote. Yours may not, many do. In this thread spederman relates his combo was. The original poster deserves to know before heading down that path.
I agree that sound "quality" is a matter of taste. Fortunately, we all bring different perspectives to help the OPer make an informed decision. Some people think gaudy graphics and halo-headlamps and giant wings look good. Some people think the louder, the better. If nothing else, the OPer should know that not every subscribes to those sorts of schools of thought. I like patman0911's take on starting a super-loud car in a quiet neighborhood or having to tip-toe the throttle early in the morning because of stupid-levels of noise. Of course, like thinkers can be dismissed as being an "Al Gore" or an "old man" just as others can dismiss the noise/rasp-embracing crowd as ricey, immature and juvenile. Works both ways, right?
In the end it's up to the OPer to decide. Discussions like this will help him realize that the gains are nominal and the potential risks -- financial and sound-quality -- are real. Only he can decide if the benefits outweigh the risks.
deftsound
Please ask me how much my supercharger cost
True. Well then i recommend he go on youtube and listen for himself. I will say that anyone with SLP 1's and an o/r midpipe, thats rice. But a decent muffler with an o/r midpipe in most instances will sound good, IMO.
