1bad65

Right now I just have the Ford Racing 4" axle-backs on my car. I have an x-pipe on order right now. When I get it installed, I may remove the cats (which could be an issue as we have inspections here) or remove the mufflers.

The question is does either of those options leave the car with a lack of back pressure or will it run just fine?

unlawfl

It will have no effect on back pressure. My 07 GT runs great without cats.

Nuke

Is that an O/R X? You'll need to turn off the O2 sensors if you remove the cats.

1bad65

It's the x-pipe from Ford Racing. This one:

http://www.fordracingparts.com/parts...tKeyField=9049

I'm gonna be ordering a CAI and tuner in about a month (money is short), I'll be doing the exhaust work then. Will the x-pipe alone cause the O2 sensor to trip? What about if I removed the mufflers instead of the cats?

onederful100

if you have inspections, and you put in an o/r midpipe, it is easier to swap the whole midpipe for the inspection. the x pipe you ordered keeps the factory cats. the easiest way to go with that x pipe is to get muffler deletes, like LM's, boomtubes, or MBRP deletes, or pypes deletes. i think the boomtubes have the best sound for deletes, but are not as loud. with the cats in, you could go w/ the other deletes and still sound good. i think if you take out the cats and the mufflers you will lose some backpressure maybe losing some low end torque, but not much to worry about, you wont even notice it.

Nuke

If you're looking to gain RWHP with the exhaust, don't knock yourself out unless you're putting headers on and even then your gains won't be huge. The stock exhaust flows extremely well. The best you can do are long tubes, losing the cats. Beyond that there's little to do to get any gains besides some variations with the X and H. The gain from short tubes has been heatedly debated here.

desslok40

Get LT headers and hi flo catted X pipe, you are still fairly legal and its a great sound, O/R pipes sound like ***, there I said it !!! lol

I picked up approx. + 20 rwhp/rwtq (dyno proven) going to hi-flo cats , LT headers and X-pipe, all for about $1000 installed. My car sounds meaner than anything on the road plus I am ready for FI in the future, so i am very happy.

1bad65

It's looking like I might be able to pull off the cats now. If so, will the x-pipe I ordered be ok? Also, once I get the tune (Brenspeed) the CEL will not be on, correct?

FYI, I'm doing the exhaust more for sound than power. I miss the sound my '65 had (289, no cats, Flowmasters) and I want to get as close to that old muscle car sound as I can with my '07.

shanec

On this topic - I'm going to have a Bassani o/r (no cats) x-pipe for sale real soon. This is the short version made for connecting to longtube headers. I just bought this in a package deal with the headers. I want the headers, but I want cats too - and that's the reason for selling the bassani o/r catted x. Again it only fits longtubes, not shorty's or stock.

Will post probably in about a week in the classified forum once the stuff is here.

1bad65

So will the x-pipe I ordered fit if I do pull the cats? And will the Brenspeed tune keep the CEL light from coming on if I do?