If I change my 05 wrx downpipe for my decatted h and s one, do I put the sensor back in or cut it off and get cel mapped out?
Cheers, Justin.
Anyone know the thread size of bosses on downpipe as I'll also need a bung.

 

Put the sensor back in, when mine was mapped it was a preference to have the first and second lambda sensors fitted.

This may vary though....