My cat was clogged up, so my mechanic when ahead and hollowed it out. I felt like I gained more power up top when in vtech. But deff lost tq at lower rpms. So now I want to put a new one on. If i match up the inlet/outlet sizes as the same on the stock cat, does that mean I can just buy a universal with those sizes and put that on? What are the demsions of the stock cat? I know about ramdom tech, but people said it sounds raspy. I know magnaflow makes one, but could not find any information on that one. Here are some other options I found, tell me what you think.

http://www.car-stuff.com/store/?N=91...264+1562+11921

http://www.car-stuff.com/store/?N=91...264+1562+11920

 

I would just get the RT cat. It flows better.
Those you linked & the Magnaflow ones are just stock replacements.

 

With that in mind, should I really be concerned with flow when our cars all ready have a "free flowing" exhaust? And get the stock replacement for the back pressure and tq gains? Sounds is also a factor here, i did hear it was a raspy tone if I went with random tech.

 

I don't see how a cat that is before the muffler can effect the sound?
It's been proven the RT cat adds HP & TQ not take away.
The problem is the expense & time to replace a cat for 1-2 HP.
Your cat is toast you need to replace it anyway. Get the good one.

 

well then thats the plan unless someone else has any information

 

you sure about that?
any change to the exhaust will affect the sound. if people say that headers give the car a 'deeper' tone, that's before the muffler, isn't it?

 

id agree that it will change the sound, not sure if it will make it deeper though

 

I had the cl-p direct-fit Random Tech cat and just replaced it with a universal 2.5" Random Tech. The new one has a slightly deeper tone and is less raspy.

 

Ok but still random tech cat? universal or direct fit?

 

MF makes a damn good high-flow cat... 200bucks or so. or do what the cheapos do, throw in a piece of test pipe and drill a hole for the sensor.

 

Yeah both Random Tech. The direct fit was ok for N/A but too small for F/I.

 

Are you serious? The number of bends in the piping can even make exhaust sound different.

And especially by removing, or having a higher flowing, less restrictive cat. More air will be coming through at a given time, and less material to deaden the sound, of course it wil sound different.

My Talon's HKS exhaust sounded amazing until I put the test pipe on for track use!

 

RT Cat changes the sound but not really anything you'd notice. Not raspy at all, just make sure you have a tight seal when it's bolted up.

 

I got it. at idle there is a little difference in sound but mostly its heard on wot

 

OK GUYS Quick question, nt trying to hijack.
I looked and there are two CAT on our cars, one right after the header and another before the muffler which one are u guys talking of and which one makes a diffrence( i want to assume the one b4 the muffler)
so which one do u guys normally change.??

 

There is only one catalytic converter on our cars, its right after the header. The other thing you speak of is a resonator to deaden sound, suppress sound. Its is also known as the mid-muffler.

To the OP I have a rt cat along with my xs headers, put them on together and I love the sound. But it is def different than stock. Don't know what part makes what sound but its not bad and gf approved. Raspy not so much. Deeper for sure.

 

Thanks.
so the RT is the one ppl usually straight pipe or i guess one cud straight pipe both the catalytic converter & the Resonator.

 

I want a cat for back pressure.

 

Now that's the info i was looking for thanks

 

The RT Cat is a 300 cell ceramic substrate with a stainless steel body. It is a direct bolt on but you need some hardware and an 02 extension. It will slightly increase the exhaust note only b/c it's flowing more exhaust but nothing you will really notice. It is not raspy.

If you need one let us know.

 

Clips were taken a day apart. Only thing different is the cat converter.



I don't know how to remove the pic after the video

 

Oh come on now, those sound clips were night and day. The RT cat sounded raspy/high pitched as hell. Right??? Thanks for the sounds clips by the way.

 

Everyone's exhaust, engine and mods are different. Mine doesn't sound like that.

 

honestly I pulled my CAT out and cut the flanges off then welded them onto a straight pipe from Advance auto (was a beautiful sight). To be honest with you other than putting on my intake from the car being stock, this was the most noticeable gain on my car period. It pulled up top and only cost me $85 bucks to get done. Never felt a loss in TQ or anything. Im running a completely new set up on the car now so I took off the straight pipe and for a magna flow high flow cat so I dont know the difference since the car is playing with a different amount of power than it did back when I had the straight pipe on. One I get the car tuned and tracked with the high flow on I will swap back in the straight pipe for a day and see how it runs.

 

Yeah i have a hollowed out cat, which i noticed a big difference up top, but loss down low. I imajin a hollowed out cat would be the same thing as a test pipe. I am not really concerned about a couple hp, since i will being going with a tuned spray. Its all about the noise.

 

No cat here and love it.. Just need to fix/replace my damn tranny... AND I HAVE A 6 SPEED!

 

define what a tuned spray is? if your doing a WET shot there is no tuning needed since the fuel and nitrous is already mixing

 

I plan on having 2 tunes. N/a tune and 100 shot. And yes this is a wet kit, the shop that i got to said if i want to most out of my nitrous a tune is a must. They will be changing things like fuel pressure, A/F ratio, timing, and etc. I know the zex smart box leans the mixture out, but I want to go beyond the box and do this project right.

 

sounds kind of weird. I dont think its really possible to have a NA tune that will maximize HP gains then turn around and be 100 Shot NOS safe. With the NOS tune all you will be doing is dumping way more fuel into the car that running straight up NA would probally be on the over kill side, then things like colder plugs that you would need for the NOS would sacrifise a little NA performance

 

Mine sounds more raspy with the RT(stock cans), idle is also louder. Good luck with the NOS project!!

 

doesnt sound too good at idle but it gets better on high rpms

 

any of you guys have a problem trying to pass the state inspection after swapping the catalytic converter? Mine has a check engine light that points to a low threshold on the converter. Now I cant pass the Texas State Inspection for my car. And its a brand new converter. Acura wants to charge 1500.00 for a stock replacement.

 

If I were to replace stock converter with the RT cat and cut out the resonator and replace it with a straight pipe would i loose too much back end pressure with a CAI being my only mod?

 

I barely passed smog with the RT cat so it seems that 300cell cats are the limit. I came close to not passing the hydro carbons portion for those wondering.

I did have rasp with headers, RT cat and magnaflow catback (2.25"-2.0" piping), with the stock cat I had no problems but there was a distinct rasp with the RT cat. Guess you just need to add a resonator on when uncorking the exhuast.

 

I have the RT 7000 series cat on my CLS6. I have XS headers and a custom exhaust. I cut off the Cat side flange from the stock headers and welded it to the front of the RT cat. It bolts right up to the XS headers or you can order a flange from Autozone or O'Rielly if you don't want to cut the stock header. The RT cat is a 2.25" in and 2.5" out. After the cat I welded 2.5" pipe back to a 18" X 6" resonator from Magnaflow about 2.5ft back from the RT cat. The round resonator is 2.5"in and 2.5"out. From that I go back with 2.5" pipe and make a 45 degree turn into a Magnaflow single 2.5" in by dual 2.25" out. The Y is right in the middle of where the OEM resonator was at the same 45 degree angle. From there it goes 2.25" tubes 1" apart that turn 45 degrees to head strait under the rear axle(if we had one) back 2.5ft to where they both turn out 90 degrees away from each other to the stock mufflers. It looks awesome from the rear! It sounds like stock but has slightly more bass, barely noticeable. At wide open throttle it is wonderful. I had no resonator first and it sounded like a shitty rice rocket. I put a crappy 4" off brand resonator on and it still sounded awful. After the Magnaflow 6" x 18" round resonator it has NO rasp what so ever! Seriously, NONE! It is exactly what I wanted. The car is no louder than stock at normal to moderate driving but sings at WOT. Highly recommended! Do not get the preassembled bolt on RT cat. It is not for the high performance application of the CLS and certainly not for the FI guys. I can’t wait to see what the MP90 supercharger does with this wide open exhaust!

I had an O2 bung welded in at about a 25 degree angle (like the o2 bung on the stock cat is angled) for the secondary O2 sensor right after the cat and no extension of any wires was necessary. My welder is awesome! There is plenty of slack left in them. I also had a bung welded onto the header with a plug for the wideband o2 sensor between the flexpipe and the cat flange on the header once I buy it.

 

Damm i about to copy that who post and hand it to my muffler shop and say make it happen. Then be done with this

 

I have the same set-up: AEM cai, resonator and replace it with a straight pipe. the rest of my exhaust is oem

My stock cat is burn from inside...scrap! And it sounds like if 12 cans of softdrinks were hangning under my car.

What kind of Cat should I get? I would like to change it by myself, so i need a bolt-on.

Is the magnaflow bolt-on?
Is the RT bolt-on two?
Do somebody know excatcly the parts number of the Cat I need?

Thanks a lot for your help

 

The RT cat is a direct replacement. There is a groupbuy going on, just follow this link:

https://acurazine.com/forums/2g-tl-1999-2003-98/xlr8-high-flow-cat-731671/

Its $295 shipped.

 

im allergic to cats, im outta here

 

Ok, thanks.

It's direct fit, but I am stock... oem headers and oem exhaust line.
i reed somewere that Oem exhaust line were 2.25 (on cl-s)

The Cat you are talking me about is 2.5

am I gone have a exhaust leak?