I am preparing to install a gibson cat-back system on my 97 expy 5.4, I am wondering if I were to knock out the contents of the catalytic converter would I be able to achieve any additional power out of the engine?
I have done this very thing on other vehicles and it helped big time, although the other car had over 100,000 mi on it when I did, so The cat was most likely plugged up. My concern is that the O2 sensors could be thrown off somehow.Or that the lack of back pressure may diminish the torque.
My truck has around 70,000 miles on it so I will assume that that the cat has become obstructive.
Can anyone shed some light on this? or does anyone have test results for a "with cat" and "without cat" dyno run?
Thanks!!

 

o

 

I would leave the cat's in place...you will definately mess up the
O2 sensors if you remove them.
The cat's should already be "free-flowing" so there won't be much of an increase in power.
You should consider making your exhaust dual or possibly putting some Gibson headers...that will give you a big boost.

HellaBig_Expedition.

 

I don't know if it's still the case but in the early 90s, I was told that the computer would recognize the lack of back-pressure and would shut the engine down. I don't know if that is still the case or not. I'd say the O2 sensor would get you if back-pressure didn't.

BrandonJ