I need a new CAT but need a few questions answered... Can anyone help me?

[Maneki Neko]

I just have a few questions about getting a new CAT...

My Car failed smog (1990 Nissan 240sx) and i took it to a mechanic and he diagnosed it as needing a new O2 sensor and a new cat. I have the O2 sensor and have been told that it is pretty easy to install, and that is fine.

I would like to know what the differance is in using a bolt on CAT or a CAT that needs to be welded on?

Can you put a bolt on CAT on a 1990 240sx?

Can you do it yourself?

Does a High Flow CAT really make a differeance?

Thanks!

[sean8564]

Are you getting a aftermarket exhaust also. I just use a test pipe till emissions than i put on my cat for inspection

[sunnys14]

You can get a $40 test pipe off ebay which you can use in place of the cat. High flow cat wont hurt your car in anyway, just gives you a bit more flow.