De-cat uppipe

[arthur t]

I have bought myself a De-cat uppipe for my 2005 wrx but now confused....

I have been doing some digging, I believe there is a sensor in the uppipe pipe that is replaced with a sensor.

Is that right correct?

If so why is this needed?

[arthur t]

Thanks for the response .

What does the sensor do?

I know u said it can be removed, but is it needed?

[arthur t]

Thanks for the response ... You learn something new every day!