dubsiren

Hey all!

So I finally got around to getting the mods done on my car I wanted: GT3 Throttle Body, IPD Plenum, GIAC Tune. BAM! Car was running AMAZINGLY. Sounded better, much faster (by clock). I was super happy.

Then……

I added the Fabspeed X-pipe.

First off, it sounds amazing. Let’s start with the good. The ONLY good. My car is next to undriveable. At low gears, when starting to drive, the engine bottoms out, jerks, and almost feels like it is going to stall. Then once going (it is Tiptronic) if I am cruising in 4th and hit some gas, it will start jerking and choking until it shifts, or I do with the manual takeover:

The shop that installed it replaced all the sensors when they installed the pipe, so we thought maybe it was faulty sensors, so they swapped again. Same story.

It is either the GIAC tune not seeing the X-pipe, or the X-pipe is borked (which I hope not, since I waited 10 weeks for it).

Any one been through this? Solutions? Ideas? Help!

rtl5009

Are all the O2s hooked up to the right side?

dubsiren

not sure - should they be? I know there are 2 banks, not sure how they hooked them up.

rtl5009

Yes.

dubsiren

So different than stock? (Sorry, I don’t know about this stuff).

rtl5009

B1 need hooked up to b1 side and b2 to b2. Also the precat sensors need to be the first ones (b1s1/b2s1) etc

Is it catted or straight?

dubsiren

200 cell sport cats.

CAVU

Trying to follow the installs.

After the initial installs and everything was running great, to not running well, What all was changed? ...all 4 exhaust sensors, the cats and the xpipe and did the tune...correct?

dubsiren

everything was running great until the x-pipe and sensors. The tune was done when the throttle body and plenum were done.

CAVU

ok. Sensors are the primary suspect unless a rag was left in the xpipe or there has been a backfire that popped a flexible connection off the intake. Might recheck all of your intake related electrical connections and filtered air intake plumbing.

Sensors: wrong ones, installed in the wrong location, wiring breakage, not connected, etc. I would run it on a durametric or PIWIS and see what the sensor voltages are reading. Might put the original ones back in their original locations.

dubsiren

all I have at home is Dash Commander. not sure what the shop has. Will check.

cwheeler

Sensors are probably backwards. Or bad.

dubsiren

I am hoping backwards. They are brand new Bosch sensors.

Dk27

Try reinstalling the old cats. This will either show it's the sensors or the x pipe.

Petza914

I have the Fabspeed 200 cell X-pipe and none of these issues. Someone messed up something with the X-pipe install, probably related to the O2 sensors? Any CELs or codes? What are they?

The O2 sensors are color coded per side - blue on one side and grey on the other. The other thing I've seen people do is not disconnect them from the connection blocks at the rear of the engine compartment and jsut unscrew them with the connection end still connected and then rescrew them in - this is way too much twisting of the wires for them to survive, but people that don't know how easy they are to disconnect and reconnect do it the wrong way and damage them - they're not cheap!