Hey guys, I'm gonna be doing some custom exhaust work and I would like to know before hand if the after cat O2 sensor on our cars (if it has one) is strictly a cat efficiency sensor like most other OBDII vehicles? or is it a MAP sensor for fuel trim adjustments? Important to kow because i would be modifying its housing to get rid of a inefficiency CEL or putting a CEL fix in the wiring and I would like to not screw up my fuel mixtures. Any experts on here, please let me know Thanks

Cheers,
Tim Quinn