Test Pipe for 7M

[87MK111Supra]

I want to replace my catalytic converter with a test pipe in order to save the cat. I don't like spending $200 whenever I have to smog the car so I would like to just keep it good until smogtime rolls around. Problem is that I have an O2 sensor after the cat so I don't know if the test pipe is going to mess up the mixture or something like that. Anybody with some experience on this? I'm running headers and would like a complete 2.5" exhaust. Thanks in advance

Jake

 

[AJ'S 88NA]

Don't think it would have anything to do with the O-2.

 

[MK3er]

The second o2 sensor will read higher amounts of HC (hydrocarbons) or un burnt gass because the cat burns up some of that extra hydrocarbon as well as nox. If the cat is replaced your emmisions will go up but the car willl run fine because the computer will notice that the first o2 sensor is reading correctly and will dismiss hte second reading or if the hydrocarbons get too far off it might go into open loop mode and stay there.

 

[CyFi6]

What year is your car? Why does it have a second o2 sensor?

 

[hvyman]

Kali cars have 2 o2 sensors.