Hi i was thinking about just cutting off my cat and running a straight pipe to my glasspack but i was wondering if there are any effects this could have on my engine. Now dont think im dumb. i just wanted more input before i have some fun with my sawzall. Im not worried about emissions i just want to know if the lack of resistence would change anything other than giving me more performance. my truck is a 94 f150xlt with a 5.0.

Thanks for your time,

Ben

 

It should improve your performance and sound both. Does the 94 still just have one O2 sensor before the cat? If there's one after the cat, that could be an issue.

Only other issue would be inspection time - they probably won't pass it without a cat.

 

Cut that sucker off!!! Its probably going to be a little louder in the cab but it sounds alot better to me inside and outside the truck. The only thing it will do to your engine is give it alittle better gas mileage and quicker throttle response.

 

I think the O2 sensor is before the cat. the good thing about Illinois is that pre 1996 cars and trucks dont get tested because they dont have an obd2 port. they dont do the hose on the exhaust test anymore, i took my moms 05 f150 in and they just plugged it in with the engine running.

 

If you can take it off and bang the contents out of it so it appears as if it is normal underneath during inspection, that would be your best bet.

 

yeah its still before the cat until it started in the 1996 models I believe...

 

OBDII has multiple oxygen sensors. OBDI you can cut off the cat or hollow it out and the computer won't know. 1995 was the last year of OBDI except for California. I hollowed mine out and welded it back on, it gives it a different sound in a good way.

 

if you have an 02 sensor after the cat what would it do if you do the same thing

 

Sean,

Do you have the 4.9 or the 5.0/5.8?


Just curious.


James,

I believe with OBDII it would send a default code to the PCM and make it run rough.

 

The check engine light comes on, which makes the PCM go into open-loop. That means the PCM will use factory default settings to run the engine instead of true readings from the sensors and that leads to bad fuel mileage,crappy running engine and the exhaust stinks like sulfur. Buy and install an O2 simulator to put in the place of the sensor. I bought mine for around 70 dollars off of Amazon. The universal one works great, it sends the PCM a mv signal and fakes it out so it doesnt recognize the sensor is gone.