Fabspeed Cay Bypass Pipes

[8202632]

Just got the secondary bypass pipes installed on my 09 CTTS this week. Let me say that there is a marked improvement over the entire RPM range. It is definitely jumpier and they reduce turbo lag immensely.

The sound is also improved. You can definitely tell from the inside (you do have to listen carefully though), but from the outside, it's amazing. Cold startup is twice as loud and during takeoff it is much more aggressive from the outside. My wife was driving and I was following her in her GL and it sounded SO much better.

I'm very happy with this mod and would recommend to anyone looking to improve overall drivability as well as much improved sound!!!

Edited April 27, 2014 by Chirag Chauhan

[hahnmgh63]

Did you go for the full Cat Bypass pipes or just the Secondary Cat Bypass pipes? I just did the Secondary Cat Bypass pipes and it is only slightly noticeable, and improvement but not much more sound.

[8202632]

Just the secondary bypass.

[PaulH]

Can i just ask i have a 2006 turbo s and was wanting to do the secondary cat delete also and i hade earmarked the Milltek Sport Performance Secondary Cat Bypass De-Cat Exhaust Pipe but i have just noticed that it says that it Must be fitted with Milltek cat-back system and requires a Stage 2 ECU remap i was under the impression the cat delete pipes just replaced the original cats bolting to the original system and did not require a remap either is this just with the milltek pipes or typical of them all what pipes have you used and experienced thank you in advance .

paul

[spooltime]

Can i just ask i have a 2006 turbo s and was wanting to do the secondary cat delete also and i hade earmarked the Milltek Sport Performance Secondary Cat Bypass De-Cat Exhaust Pipe but i have just noticed that it says that it Must be fitted with Milltek cat-back system and requires a Stage 2 ECU remap i was under the impression the cat delete pipes just replaced the original cats bolting to the original system and did not require a remap either is this just with the milltek pipes or typical of them all what pipes have you used and experienced thank you in advance .

paul

I'm not familiar with the Milltek bypass pipes. The most commonly used bypass pipes on this side of the big pond, Fabspeed's and Leistung's, are both designed to replace only the secondary catalytic converters and bolt right up to the remaining factory exhaust system. I have a set on my CTTS and believe it's the single best mod I've done. The primary catalysts are integral with the downpipes, and have the pre and post 02 sensor ports on them. Most guys leave these unmolested. A secondary bypass install does not require ECU remap, but obviously a remap will further enhance the performance of the vehicle. Personally, I would advise against doing an aftermarket exhaust unless you're just looking for more noise; they don't really offer much incremental performance.

[hahnmgh63]

Looks like the Milltek pipes are a slip fit in the rear to their rear exhaust, similiar to OEM but it may be a different diameter. I have a set of Milltek Catless downpipes for my Audi RS6 and they are about 1/4"~6mm larger than OEM and also meant for their own rear slightly larger pipes. Since Milltek are somewhat a local (UK) company you may want to call them. They have excellent quality, as good as any and better than most. Otherwise you could see if their is a Fabspeed distributor around but in the UK I doubt they could compete with Milltek.

[PaulH]

Looks like the Milltek pipes are a slip fit in the rear to their rear exhaust, similiar to OEM but it may be a different diameter. I have a set of Milltek Catless downpipes for my Audi RS6 and they are about 1/4"~6mm larger than OEM and also meant for their own rear slightly larger pipes. Since Milltek are somewhat a local (UK) company you may want to call them. They have excellent quality, as good as any and better than most. Otherwise you could see if their is a Fabspeed distributor around but in the UK I doubt they could compete with Milltek.

Thank you for your reply i will give them a ring :cheers:

[PaulH]

Can i just ask i have a 2006 turbo s and was wanting to do the secondary cat delete also and i hade earmarked the Milltek Sport Performance Secondary Cat Bypass De-Cat Exhaust Pipe but i have just noticed that it says that it Must be fitted with Milltek cat-back system and requires a Stage 2 ECU remap i was under the impression the cat delete pipes just replaced the original cats bolting to the original system and did not require a remap either is this just with the milltek pipes or typical of them all what pipes have you used and experienced thank you in advance .

paul

I'm not familiar with the Milltek bypass pipes. The most commonly used bypass pipes on this side of the big pond, Fabspeed's and Leistung's, are both designed to replace only the secondary catalytic converters and bolt right up to the remaining factory exhaust system. I have a set on my CTTS and believe it's the single best mod I've done. The primary catalysts are integral with the downpipes, and have the pre and post 02 sensor ports on them. Most guys leave these unmolested. A secondary bypass install does not require ECU remap, but obviously a remap will further enhance the performance of the vehicle. Personally, I would advise against doing an aftermarket exhaust unless you're just looking for more noise; they don't really offer much incremental performance.

Thank you for your informative reply i know have another couple of options maybe :clapping:

[hahnmgh63]

Fabspeed does also make a Downpipe which replaces the front Cats too but removing the Downpipes is a royal Pain in the A%$. Milltek probably makes a set or would do a custom set of downpipes too but like I said, the install is 5 times the work of doing the Secondary Cat bypass pipes.

[PaulH]

Fabspeed does also make a Downpipe which replaces the front Cats too but removing the Downpipes is a royal Pain in the A%$. Milltek probably makes a set or would do a custom set of downpipes too but like I said, the install is 5 times the work of doing the Secondary Cat bypass pipes.

Thanks but i am only really interested in replacing the secondary cats its a nice mod without getting to expensive and later on i can always replace the mufflers to increase the growl etc :drive:

[spastik monkey]

Secondary cat delete by Fabspeed got wrapped up on my 04TT yesterday. Massive improvement, plus the sound is great. Louder, but not obnoxious

[hcheun]

I was interested in doing this on my 04 cayenne, but am worried about passing smog. Anyone had issues with this? Wanted to get your thoughts and what you guys did to fix if you didn't pass.. Thanks!

[Enzo955]

So the secondary cat deletes worked well on the 2004 CTT? Looking to get a pair for mine? Any sounds clips or videos? Can only find them for the newer Cayennes.

[hahnmgh63]

The '03 through '06 CTT pipes are all the same.

Not sure on smog depending on your state. My CTTS passes smog in WA with the secondary Cats deleted, running on only the Primary Cats. Their isn't a state out there that can go to the depth of an EPA cycle for smog but many do varying (or no smog) levels of testing. Only 4 counties in WA state do testing, not a statewide requirement and supposedly going away completely in 2 yrs. Some states do a tailpipe sniff, some do it on a dyno, some only read your OBDII codes, some don't test...

[hcheun]

The '03 through '06 CTT pipes are all the same.

Not sure on smog depending on your state. My CTTS passes smog in WA with the secondary Cats deleted, running on only the Primary Cats. Their isn't a state out there that can go to the depth of an EPA cycle for smog but many do varying (or no smog) levels of testing. Only 4 counties in WA state do testing, not a statewide requirement and supposedly going away completely in 2 yrs. Some states do a tailpipe sniff, some do it on a dyno, some only read your OBDII codes, some don't test...

Thanks hahnmgh63, unfortunately i'm in CA where we're force to do it every 2 years. The smog place I go to does OBD codes and tail pipe sniff (because they don't have a 4wd dyno)

Hope someone here in CA can chime in on this, as I'm really hankerin on doing this upgrade!

[clarksongli]

Only certain counties in California require smog testing.

My recommendation is to just keep the secondary cats around and swap them in as needed. My guess will be that the car will pass smog with the deletes though.