exhaust (cat) questions

[discoman]

My 96' Disco has a crack in the RH exhaust right between the first 02 sensor and the cat. The resulting fudha-fudha-fudha noise is somewhat of a bother. It's not overly loud but i'm going to get it fixed up none the less.
I'm a bit old skool and not used to sensors and ECU's and what or how a person can modify or change something on these systems. This might be straight forward to some of you and sound like a silly question but i need to know.
What happens if I git rid of the cats from the exhaust system? I know WHY they are there. I saw a second O2 sensor after the cats and thought that by removing the cats, that might mess the ECU up by having a dirtier exhaust pass by the second sensor. I live B.C. Canada in an area where pollution laws are on the lax side.

 

[NHESS81]

I am not sure. Trust me that fudha sound gets soooo annoying, I have sheard bolts at my manifold to y-pipe, and booooy, makes me sound like a diesel, not to mention the O2 on the left side is thinking im running lean, so the truck is in super rich mixture mode, I get horrible acceleration and very poor gas mileage...need it fixed ASAP....so anyway, I think you will have some issues. Why not just keep the cats? Too much money?

 

[discoman]

I haven't checked out prices on cats yet, but I'm sure they are up there. Mechanic friends of mine are always telling me to cut the cats out on anything because they are a nuisance and plug up and all that. I'm posting this question just to see what others have done and to see what the possible results of removing cats might be. In the end, I might keep the cats but just want to explore the option of ridding them. I wonder, is there a way to fool the O2 sensors??? Hmmmmm!

 

[Moose]

(1) Do you live in an area where emissions testing is done? Do you ever plan on moving somewhere where it is a requirement? If the answer to either question is "yes" don't get rid of them.

(2) Do you find your existing mileage to be too good? Removing the cats and O2 sensors will trip the CEL, and will make the truck go into "full-rich" mode, with maybe a 0.00001% increased in performance and a ridiculous amount of additional fuel per gallon.

(3) You'd probably have to reprogram the Engine ECU to get around the oxygen sensors.

 

[discoman]

Nah, there's no testing in my area and they will have to pry my cold, stiff fingers off the steering wheel of my rig before I move anywhere else.
I just bought the Rover so I haven't got any indication of the mileage it gets yet.
I work in a fabrication shop so I was thinking of removing that section of exhaust and getting one of our welders to TIG up the crack and then reinstalling it. That should solve the problem for now I figure.

 

[beemer]

I have a 95 D1 (4.6) with single O2's each side, cats were rattling after stealers tossed them on the ground during extended 100K mile warranty work. They started to plug up and melt into a restricted mess. Stealers crap way over priced and restrictive.
CarSound High Flow cats out flow Rover's, pass smog and flow with a "just detectable" difference vs gutted cats, flow a lot better than new Rover cats besides I paid $53 USD each. You want a pair of flat cats, they are easy to replace, you'll need to add a few 4" lengths of pipe. The rear O2 will set off a dash light, nothing to do with how the motor runs. Weld up that crack and install new gaskets between manifold and down pipe as any leak will allow air into the exhaust for a false F/A signal to the first O2 sensor. First O2 is for your F/A ratio.

.....=o&o>.....

 

[discoman]

Great stuff guys!!! I'll check into it.