Is the heat sensor absolutely necessary for r33? I am planning on having straight pipe from collector to rear muffler put in, with small section easily removable so catalytic can be installed for our mandated emissions testing done every year. But I see temp sensor in test pipe on car now. Will car run on funny maps if it sees no temp from this gauge, or is it just to turn on "idiot" light on dash when temps are too high with-in catalytic? Thanks for all opinions.