Removal of Cat Converter

[84celicasupra]

I have a newb question.

If I remove my catalytic converter on an '84 mkii and replace it with a straight pipe, will this generate a check engine light or cause any problems for the engine? The car is emissions exempt so I'm not concerned with higher emissions, I just don't want anything lighting up on the dash or to damage the car in any way.

Thanks!

Josh

[Morg_9]

No, there's no sensors in the exhaust after the catalytic converter.

[84celicasupra]

Thanks... As a follow-up what's the difference between just welding a piece of pipe in place of the cat vs. getting a test pipe. I see that the test pipes can be bolted up and I guess removed and put back in place with a cat, but I also see some of them have a fitting on there that looks like for a sensor or something. Do I need to buy a test pipe or can I just have a pipe permanently welded in?

[4SFED]

Thanks... As a follow-up what's the difference between just welding a piece of pipe in place of the cat vs. getting a test pipe

one is welded the other is bolted in

If you ever want to sell the car or you ever need a cat put back on for if you move to a place with smog nazis then you might want to bolt in rather than weld

[EwGoetsch]

cut that bitch out, go to auto zone, get an adapter, and find some pipe. My buddy once put a fence post on his old truck, still had mud caked inside of it.

[84celicasupra]

Thanks for the info guys, so there's no reason to buy a $100 test pipe then, there's no sensor fittings or anything that are necessary to have the car run right. I'm off to knock over a fence!

[83CelWA]

You may want to put a resonator in place of the cat instead of just a pipe, it will kill off the angry bumbebee sound at the higher revs. I have been running the tube style glasspack from thrush for some time now with no problems.

[1SupraMk2]

You may want to put a resonator in place of the cat instead of just a pipe, it will kill off the angry bumbebee sound at the higher revs. I have been running the tube style glasspack from thrush for some time now with no problems.

Agreed, I bought a 12" glasspack from Summit Racing for about $25, it sounds much better than the ringing of an empty cat or straight pipe.

[84celicasupra]

Thanks for the advice about the glasspack/resonator vs. straight pipe!

[gomez]

Wouldn't removing your cat mean that you fail your emissions or MOT test (depending where you are from)