I have an 05 with tune/pulley. Stock headers. H pipe exhaust. I'd like to remove the CATS to make the car louder and also hoping to get some more "pop and gurgle" out of her. Thoughts on this? Anyone have a similar setup? Thanks!
Removing the Cats
- Thread starter MNJason
- Start date
I run mine without cats all of the time - virtually the same set-up as you. Yes, louder and more "personality".
twobjshelbys
GT Owner
I presume you don't have emissions testing there. You will need a tune that disables the rear O2 sensors or you'll have a persistent check engine light.
spartan
GT Owner
I went back and forth deciding to remove the OEM cats. Decided to leave them so I cant comment. With the cats on its not very loud so if you want loud take them off.
Im comparing mine to two local cars with the Ford Racing Headers and Borla exhaust which I think sounds perfect. I would say most people think its too loud. Not for me.
Yes, no emissions here. I have a pulley and tune so I assume disabling those sensors is not a big deal?
Thanks for all the comments and help!
Yes, no emissions here. I have a pulley and tune so I assume disabling those sensors is not a big deal?
Thanks for all the comments and help!
twobjshelbys
GT Owner
If you have a sct tuner or equivalent your tuner should be able to send one you can load. Doing so resets all system readiness and pending codes. Your tuner box might be able to read the status but I'd recommend getting a obdii Bluetooth reader and just keep it plugged in.
Ford Racing used to make Cat delete pipes. Just maybe you can find someone who is not using them...
Do you think H pipe plus no cats is much louder than headers and Ford racing exhaust? The tuner I am talking to says yes. MUCH yes.
Sinovac
GT Owner
Xcentric
GT Owner
NorthwoodGT
GT Owner
there are also some after market companies making a test pipe with mini cats that include the bungs for the O2 sensors. they've been on fleabay in the past. the Borlas look interesting. wonder how they sound compared to the OEM?
Bill Briley
GT Owner
SS Ford Racing Headers (No Cats) and stock muffler .......The sound is intoxicating !!
Pull into a Cars and Coffee and watch the crowd gravitate toward the GT Symphony .
Pull into a Cars and Coffee and watch the crowd gravitate toward the GT Symphony .
Sinovac
GT Owner
soroush
Ford Gt Owner
- Aug 8, 2007
- 5,256
I have never seen or heard of this set up, usually the first that goes in an exhaust install is the factory muffler. do you have any vids?
This is essentially a question of comparing a system with a muffler and one with absolutely no muffler. No muffler is quite a bit louder. Note that on your current set-up ==> cats + h-pipe, the cats do a fairly reasonable job of acting as a pseudo muffler. Replace those with bypass pipes and you essentially have no muffler action at all.
Xcentric
GT Owner
By "Ford racing exhaust," do you mean the Borla/FRPP muffler?
If yes, then I think no cats + H-pipe will be louder. The Borla/FRPP muffler with long tube headers mutes the noise at idle, light throttle, steady throttle. However, open the throttle and it is LOUD. It sounds like there is no muffler. Like you might expect a valved muffler to sound. I think the Borla/FRPP muffler takes out some of the rasp of a rear exit header system and adds a bit of baritone/bass.
No cats + H-pipe would not have anything to quiet the exhaust except for the minor effect of the cast iron manifolds. I have not heard this particular setup, but that is why I think it would be louder.
The Borla pipes are pricey. Why not just gut the cats? If you want to be able to return to stock someday, I'm sure there are tons of cat pipes in forum members garages. I'll sell you mine for less than the cost of the Borla pipes.
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NorthwoodGT
GT Owner
I found the small cats. they are 3" in x 3" out and a total of 9" long made by Magnaflow. somebody was making a test pipe for the GT with these cats already installed and a bung in the pipe for the O2 sensor.