Exhaust Question

[fisho mick]

Gday all i have a couple of questions to ask regarding my 1uz into 91 surf going to run twin 2 1/4 into 2 1/2" single exhaust
1.do i have to use two cats or can i use a y pipe and use a single cat
2.do i have to use the sub o2 sensors
any info would be great

 

[Zuffen]

As best as I can work out the rules in all states say you need to run all the EPA equipment on the car that relates to the ADR's in force when the motor was built.

This means a UZ engine must run cats and o2 sensors.

The o2 sensors are used a lot by the ECU to give you fuel economy so a good reason to keep them.

Cats don't rob power from a vehicle if they're in good nick and of the correct size.