what's the difference running w/out the o2 sensor..i noticed my Check engine light on..but would the car be a lil bit slower since the ecu is not reading it??

 

Fuel milage may decrease. If you go without running an 02 sensor I strongly reccomend an 02 simulator. All an 02 sensor is an air/fuel ratio sensor. Letting the PCM know how much fuel to add or cut to the engine.

 

with the engine check light on the car runs in safe mode and yes you will def burn more gas and probably less performance.

 

If you look at the odb2 readings, the car will run rich/lean/rich/lean back and forth really fast over and over. This is facilitated by the 02 sensor.

If the 02 sensor isn't working correctly, the computer can't continually modify the a/f and you won't make as much power.

 

yea my gas mileage was a lil decrease..and performance feels like it can push a lil more..i had some cheap test pipe and it crack on me..and i couldn't unscrew the 02..cause the treads are gone..now i need new one =(

 

Right now my rear 02 sensor is not working. The honeycomb inside the cat has broke free and broke the tip of the 02 sensor off

I have another 02 senosr, but I first want to get another cat or gut it....or just get a high flow cat.

Anyways, everyone has anwsered your question, but w/ the rear 02 sensor on mine not working and throwing the CEL I have not really noticed a fuel decrease. But, That is probably due to in being the rear sensor.

 

This has been known to happen. Especially if you run rich you can toast your cat. Some people find out because of the rattle, some notice because the secondary O2 sensor is shredded and they get a CEL.

Secondary O2 sensor has no effect on your performance. It's emissions only. But check the CEL code with an OBDII scanner to make sure it's nothing worse.

Primary O2 sensor would have serious performance ramifications.