Fox X pipe question

MrPerfect2

Active Member
Jul 23, 2019
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I would like to get a bit more sound out of my 91 - I have a BBK X pipe for long tubes - was thinking to cut my orig back 2 cats off and weld this on - it has air tube inlet but no O2 sensor holes - will car run ok if these sensors are removed ? Or should I just cut the back cats off and keep orig piping and just use less of the X pipe?
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RaggedGT

check back later..
Mod Dude
Jul 20, 2014
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www.stangnet.com
If you are welding the X pipe in, spend a few bucks at the parts house first on a couple O2 bungs and weld them into the x pipe- you really don’t wanna ditch your O2 sensors
 

Mustang5L5

This is a big reason why I pulled it out
Mod Dude
Feb 18, 2001
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If you want more sound, just cut the two front cats off and weld in straight piping there. Keep the o2 bungs though.
 

Olivethefet

Slap me as well as point and laugh
May 17, 2018
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My car doesn't have cats. Sounds alright and has the O2 sensors. I would not recommend removing the O2 sensors. With no cats on the car it does smell heavily of gas. Not a big deal rolling down the road, but sitting at stop lights with the windows down can be a bit smelly.
 

MrPerfect2

Active Member
Jul 23, 2019
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Cut off old H pipe area and got the X fully welded on the car - old pipe had rusted holes and a broken hanger ( causing it to bounce ) there were no o2 sensors in this area , just the air tube ( hook that up too ) car sounds a bit quieter but lower rumble tone ( I like it ! ) probably was higher noise from the rust holes - $100 labor well spent !
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Mustang5L5

This is a big reason why I pulled it out
Mod Dude
Feb 18, 2001
31,330
7,579
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Massachusetts
The O2s are mounted up ahead of where the pre-cats would be. First couple inches of the H-pipe. There are no rear o2's on a fox.
 

MrPerfect2

Active Member
Jul 23, 2019
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From what I read from people who cut both front and rear cats off and looked inside them - they look like the same honeycomb - they said these are 4 cat systems - btw I sold back 2 cats for $80 scrap guy ( I had no idea they are valuable )
 

MrPerfect2

Active Member
Jul 23, 2019
186
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Washington DC
The more I drive the car with X pipe , the more I like it ! Feels like a power boost when rpms hit 2500 - sound is not much different ( maybe a bit louder , but same rumble ) I have no idea what mufflers are on it , lol -
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