#5, "RE: Do I have a bad O2 sensor?" In response to In response to 2
There are two. The upstream is closer to the engine, and the downstream is in the exhaust piping after the catalytic converter. You need a special o2 sensor socket that lets you slip the wires through. Its easy for a pro to do, should be less than 15 mins, but don't know how hard it would be to do yourself...oh btw, the stock downstream sensor is 120 at norco mirsu with club dsm discount. The upstream (which is the only one that would cause major fuel consumption probs) is a little cheaper - stick with OEM parts. But don't replace that sensor for no reason - try to check out the Check engine light code because that will tell you specifically if its the o2 sensor...
