GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

3 inch catless (how to?)

Fahrenheit 608

New member
Location
Ohio
Car(s)
07 gti Fahrenheit
Hi names Laken I have a 07 gti Fahrenheit and was wondering if my car will throw a code if I install a 3 inch cat-less downpipe and if it will what can I do to help it, such as an o2 spacer or something else?
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
It will code catless...mine did. Results with a spacer are back-n-forth. Some have success with a spacer...some do not and still get coded. My angled spacer works. Was/is a $10 ebay spacer.
14012082_1096567480433724_325737411_n.jpg
 

snobrdrdan

former GTI owner
Adding a downpipe alone will only add a little bit of power and more noise.

To FULLY utilize the power/gains from a downpipe, get it tuned. And with a Stage 2 tune, it'll turn the CEL light off (caused by the downpipe)
Problem solved
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
A stage 2 tune on the FSI doesn't turn off the CEL for it when catless. Unless they have a test pipe tune. So it needs to be asked for. Just contact the tuner you choose and ask.
A custom tune or tuner must write in a patch for it not to trigger a CEL. I had the catless patch when I ran the Driver Motorsport tune, but I had to request it even then.
 

snobrdrdan

former GTI owner
Regardless, a tune can/will get rid of the CEL (properly)

Like ROH ECHT said, spacers are definitely hit or miss if they'll work. So it could just be $40 wasted if you still have the CEL, which could've gone towards a tune instead if that's what you're eventually planning anyways.

And to go Stage 2 on the cheap....ebay downpipe + tune
 

GIACUser

Master Wallet Mechanic
Location
SoCal
Hi names Laken I have a 07 gti Fahrenheit and was wondering if my car will throw a code if I install a 3 inch cat-less downpipe and if it will what can I do to help it, such as an o2 spacer or something else?
It is good that Ohio did away with tailpipe testing this year. As mentioned some tunes, like APR may suppress CEL caused by installing catless or hi-flo cat which takes care of CEL problem in terms of the light being on just for your own preference but if you live in one of the 7 counties in Ohio that require testing, will cause you to fail the ODBII test they use. If you have to pass that ODBII test and you have a tune that suppresses the CEL you would have to switch back to a stock like tune just for the test.

Going completely catless, does make your exhaust stink (sidenote). You can use spacers to fool the ECU into thinking there is a properly functioning cat in place. The system is looking for a significant difference in readings between the 2 02 sensors. The way to do that is to pull the 2nd 02 spacer out of the exhaust stream by just the right amount to cause the readings between the two sensors to have proper difference. My preferred spacer is this one - Vibrant J
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
That's a nice one because of the interchangeable jets/ports. This likely takes 'LUCK' out of the equation.
 
Top