Fabspeed Motorsport

Hello All,
My name is Phil and I am reaching out from Fabspeed.
This is a very sticky topic for owners everywhere. There are huge upsides to both and downsides to both.
Pro's
Sport Cat's:
1. No check engine light
2. Low fuel smell
3. great sound
4. 93% Free flow when using HJS High flow catalytic converters
Con's
1.Price much more expensive of Cat bypass
2. Leaves some power on the table

Cat bypass
Pro's
1. Raw sound
2 100% free flow
3. The most power you will be able to get out of the part
Con's
1. Smell
2. Check engine light
3. Issues with emissions in some states

If it is not a track only car we highly suggest going with the sport cats. It is less of a headache for emissions, CEL, and smell. Also if you are going with cat bypass normally you will go with a performance muffler or no muffler. If it is a track only car to get the real benefits of the Cat bypass you should go with the full exhaust and you might end up with going over DB ratings at some tracks. We do make some turn down tips to help out with sound but now you are fighting sound as well.

I hope this helps

R_Rated

I'd add that in a turbo car the extreme volume is significantly muted vs in an NA car due to the turbos. Also - with the O2/mini cat bungs the CEL is a non issue.

Soapman72

I would say that the smell issue has much more to do with the ecu calibration in whatever front engine car(s) you are referring to. The Porsche may self adjust for the mods much more accurately and keep the a/f ratio in check. Many cars are significantlyricher than optimal in stock form anyway, in an effort to reduce detonatin (pinging). The relative positon of the engine cannot possibly impact the smell any more than the color of the interior in the car would.

PCA1983

I have bypass pipes on my S/X51, and the sound is AMAZING with PSE turned On! It sounds more like 5.0 L than 3.0 L. And it's loud when you want it loud. The two distinct turbo whistles in Sport+ mode add unique drama that a naturally aspirated engine does not have.
With PSE turned off, the sound level is acceptable, and my wife and neighbors don't seem to notice. Being an old gearhead who grew up loving cars from the 50s, 60s, and 70s, the smell doesn't bother me. I just want that serious sound! A guess is the turbos spool up a little quicker and might provide a little more power, but have not seen any dyno curves that show this. I'm lovin em!

Das14444

Ttz06vette

Das14444

Ttz06vette

You can run without a tune but it does not maximize performance benefits. For weekend use and sound you vould live with it but you still would need to deal with the CEL and emissio. Inspection issues.

Das14444

Soul Performance

The CEL should not effect the drivability of the car, we have also had some success with O2 spacers to help minimize the CEL occurrence so that is also an option for you

- John Gaydos

PCA1983

Yes. A nuisance CEL came on after 30 miles when stopping for gas and restarting. I did use the mini-cat extensions on the O2 sensors. I'm assuming my indie did the installation correctly, and did not damage an O2 sensor wire. Had em on for 4 months now. I'm going to buy my own resetting device and see...
My indie has em on his GTS installed like mine, and he says he has had no CEL. But he does have a COBB tune...
For me, the sounds with PSE on are worth the CEL nuisance. Sounds more like 5.0 than 3.0 TT. And it is still reasonably quiet using the muffler, when going past speed cops 🚔👮. 😀

Das14444

PCA1983

Has not happened on mine, in 4 months / 2000 miles.

Das14444

Ttz06vette

The light is a PIA and will be an issue at some point for resale or when bringing to dealer for service. Best to get it taken care of with O2 spacers or tune to shut off the code from throwing.