Do they make O2 simms for the front 2 sensors? And if so would emissions check for something like that? .... sorry for the dumb question...first emissions test coming up I know I should pass b/c I just bought 2 random tech cats, but what about the O2?? Do the fronts affect how the car runs?

Thanx

 

front o2 sensors are VITAL to the function of the engine. they are what monitors A/F ratio.

you cannot put sims there.

 

The front/pre-cat O2 sensors can not be replaced by sims. The PCM needs their feedback to control the A/F ratio, for purposes of emissions and fuel economy. You could have your PCM reprogrammed to operated in open loop (no O2 sensor feedback), rather than closed loop (O2 sensors feedback). But it is quite liely you would end up with increased emissions and poorer fuel economy, and the sytem would no longer "adapt" to modifications.