I've gotten the itch to replace my stock catalytic converters. No codes or anything, but they are over 11 years old with over 150k miles on them. Plus I've got the Mina Gallery mufflers and a custom x-pipe, so I might as well complete the package.

After doing some research here, Nameless seems to be best option. I'd like to hear some reviews from members who have installed aftermarket performance cats, either from Nameless or any other brand. Anyone?

 

Cats are pretty much cats. 200 cell is 200 cell. You can get magnaflows for 90$ a piece.

 

The fact that I'm in California throws a wrench into things...

 

You could always move.

 

you could have a set mounted with flanges and remove them when you go for inspection and then put the sport ones back. Not a big deal.

 

Yeah, I had considered that. I guess once every two years isn't bad.

 

Once every 2 years it a no brainer. Do it yourself on jacks or have a shop charge you 150$ to swap them in and out.

 

Another problem with being in California is that a lot of places won't sell or ship to you. So that narrows my replacement options considerably. I'd rather not have to go to a shop and have them custom make something. I want to just do a bolt on replacement myself.

 

ALSO, I'm pretty happy with the way my setup sounds now, with the x-pipe and Mina mufflers. I don't really want it any louder. I wonder if I should just get regular replacement cats instead of hi-flow.

 

Anyone know what size aftermarket universal cat would fit?

(for example, "2 1/4" inlet/outlet by 24")

I have a bad RH cat (07 XJR), and would like to order a set of generic 200 cell replacements and weld them in

The aftermarket bolt in replacements I have seen look pretty cobby (and are $$$)

Thanks

 

The Nameless cats will likely affect sniffer test if you have and will most definitely affect sound.

 

Has anyone replaced (just) XJR cats (with free flow)? Any noisier?

My 07 XJR is noisy enough already (exhaust noise in interior during mild acceleration). Assume this is factory noise tuning (the Sound of Power!). Would hate to end up with a steady throttle (cruise) exhaust drone

Are the Xj8's quieter than the XJR's? Do they use different exhaust components (eg mufflers, resonators)? It seems that the cats are the same (XJR and XJ8)

Making a performance car noisy is dead easy (ask any 17 yr old). Making one seamlessly quiet is a tough engineering challenge. Just look at the exhaust system in an M5 (or most AMG cars)

 

I like to keep things simple so I just placed my order with Jason at Nameless. He estimated the build-time to be 2-3 weeks. He was very responsive to all my questions.

 

will be louder!!!!

 

I'll just have to make do

 

Hisport,

My first mod on my 05 XJR was to install an X-pipe in place of the center resonators. The car had a noticable noise from the exhaust under acceleration but was quiet at idle from inside the car.

Not able to leave things alone and on a quest for more power, I made my own straight pipes to replace the cats. With the straight pipes and the X-pipe the car was way too loud.

Not wanting to give up on the straight pipes, I replaced the X-pipe with a Magnaflow muffler with a internal x-pipe. The car now has a raspy exhaust note and can be heard from inside under acceleration but does not drone while cruising.

I am still running the stock mufflers although I have changes the tips. The exhaust may be too loud for some but I like it and can always reinstall the stock cats if needed.

Woodford Jag

 

True! I have Magnaflow stainless 200 cel cats on my ole ZX and they're great...

http://youtu.be/vSSPp5iAZgw

On eBay you can get them for $78 each shipping included

 

Initially I replaced the OEM cats with 100cspi units and left the rest of the exhaust alone.

Performance was definitely better but I had 180,000km on the old cats so I cant tell you how much was due to replacing the old ones.

Sound was not much louder but the note changes.
To put it another way I could still hear the supercharger wine.

That all changed with the exhaust changes.
I now have a xpipe and rear boxes only. Its too loud but does sound great.
I can no longer hear the superchargers

As for pipes I have 3in cats and x pipe. This goes down to 2.5in after the xpipe

For the boxes I have magaflow/lukey VT's. So when I nail it the flaps open up and I effectively have open pipes.
I will be putting cutting down the noise a bit by putting in some boxes where the second set normally are. The aim being to quieten down the system but keep the tone. Ill go as far as being able to hear the supercharger again.

I guess the down side of the exhaust changes, in my mind anyway, is ive lost the stealth factor. Id rather not draw so much attention

I posted detail and pics of the cats when they were fitted if you search for it

Cheers
34by151

 

UPDATE: I fitted my Nameless cats, and have been driving with them for about a week and a half now. I can say there are definite improvements in the driveability of my car.

First off though, performance was a bit sluggish for the first few days. My car takes a while to adjust to any changes, whether you reset the battery or not. It'll drive like crap for a day or two even if you put in a fresh air filter!

However, there was one improvement that was instantaneous. I've complained in other threads before about how my braking power is really poor, and how it felt like there was no engine braking at all, which subsequently would cause horrible brake groaning and squealing on every stop. Well, the new cats completely changed all that. The car now comes to a soft easy stop every single time. Braking is effortless again. The old cats were probably clogged to some extent, causing excessive backpressure or inaccurate o2 readings, which affected the engine management.

I also complained in a different thread about engine pinging upon light acceleration. That too is longer an issue. I still heard pinging the day after installation while the car was still adapting, but I have not heard it since, not even once. And I've tried to recreate it.

DISCLAIMER: The following are my thoughts and opinions only. There is no dyno or any any other type of hard evidence showing any sort of power increase. Please do not start asking for any such evidence or start criticizing my "butt-dyno". Thank you.
Regarding performance, low end power is pretty much the same...the extra oomph comes in the mid to high range. The power seems to just keeps coming and coming. I would never really go above 70mph before...now I frequently find myself at 80 or 90 without even realizing it. Keep in mind that the difference is not night and day. If you're not extremely well acquainted with how your car normally operates, you might not notice any difference. It's a subtle improvement, but it's definitely there.

Regarding sound...there is a slight change and volume increase. I have an x-pipe and Mina gallery mufflers. In concert with the new cats, the exhaust now has a slight rasp to it and slight burble on deceleration. Still no droning and cruising is still subtle. Idle sound is deeper and more rumbly. Pressing the go-pedal with the windows down will make you smile, if you're into that sort of thing. I'm frequently turning off my radio these days.

I have one complaint...the exhaust smell is more noticeable. I've read this is a common issue with high-flow cats and that it may dissipate as they break in. I've been keeping an eye on my fuel trims in case there's a leak at the flange (the first place to look), but everything seems fine. I'll update if there's anything new.

So, all in all, I am very happy with this upgrade. The car has increased power both in going and stopping (actually, the braking issue is what I'm really the most happy about). Recommended.