i have all that shit, minus the cap and rotor.

 

I thought you said you hadnt done a tuneup since you got the car.

 

i clean my air filter weekly, have a new fuel filter, and plugs and wires, thats it.

 

How bad will a bad O2 sensor throw off ur gas mileage

 

pretty bad.

 

bad enough to where i got about 150 miles out of a full tank on a v6 probe...terrible...o2 sensors own your gas mileage, and performance and even though you might not race your car it still isnt good because a bad o2 sensor will screw up your air/fuel mixture also

 

At WOT (at least with my car...), the ecu goes into open loop operation, where it basically ignores the o2 sensor. A bad o2 sensor doesnt cause a performance problem, only a gas mileage one.

 

Fix the problem yet?