to gut or not to gut?

[dudewerx]

So I replaced my rear driveshaft last weekend and while I had the exhaust out an idea came to mind....

On a totally stock exhaust what would be the pros and cons of gutting both cats with the plans on adding a high flow muffler down the road?

[johnegg]

let's see,

global warming comes to mind,

that would be a con.

 

i'm not sure what you would gain, more power, or performance.

i doubt it would be much in either case, but i do not really know.

 

i have heard that with the "anti-fouler" spacer on the rear o2 sensor,

you can run with no cats.

so gutted cats would be a no brainer.

 

but what if it did not work

and you were left with a CEL and no way to pass emissions testing.?

then what?

[dudewerx]

The CEL light was my biggest concern really. in the area of Virginia I am in emission testing is laughable so that's not a big worry for me. I gutted the cats on a Mitsubishi Lancer I had and it opened it up quite nice and with the intake the thing pulled really hard, butt dyno wise. It made the CEL light come on though but strangely improved my fuel economy by like 7mpg. I could go like 380 some miles on 10 gallons after that.

 

So, does anyone here run a cat less exhaust?

[twisty]

ive gutted cats on a few cars that arent in emissions required areas, even a few that are here in the valley that requires emissions. i dont think it is much different performance-wise over a working cat, but if it is already plugged, there is a lot of noticeable difference. mainly due to the exhaust not being super restricted anymore. the latest one was a 1978 buick le sabre.