this may sound dumb to some people but i manged to build a car from scrath together evo 5! mirage body! any ways i some reason was thinking 02 sensers were only for smog> haha dumb me any ways never realy tryed to use 02 sensers well i manged to find 1 front 02 senser in my garage from a evo 9 i poped that in today. i think there should be 1 more 02 senser? FOR THE CAT PART. I THINK?

any ways question is how bad is it to drive with no 02 sensers?
or even just 1 02 senser?

i can smell stinky exhaust when i step on teh gas pass 3500rpm's when my window is down stinks like crap/.. smells like when your forget to plug your maf senser in and start you car up but not as bad.

any ways yeah any help would be great thanks

 

also im all stock except 255 fuel pump. blitz blow off and ic piping.
stock evo 5 ecu(which are hard to flash) till i can get a evo evo 8 ecu to flash and use instead

 

also its a evo 8 motor with evo 9 turbo 3inch dp with aftermarket 02 housing and 3inch testpipe with a plug where i think im missing my second 02 if i need it?