yea, what xtremers says. the o2 sensor should be placed somewhere inbetween the turbo and the cat. the cat would affect the readings somewhat, b/c it would change the partial pressure of the individual gasses the sensor is measuring. that's the reason why you can use an o2 sensor to determine if your cat is working.

I think that the wideband's lifespan is one of those things that's really dependant on how you treat it. I think it was the NTK sensor where they said you should always have the temp at the sensor below 1560 F, and never run the car w/o power to the sensor, b/c carbon will deposit on a cold sensor, limiting it's life.

50000 miles still seems kind of optimistic though. I've heard around 30K. comments?

2gnt: '99 RS-T, killed by a toyota, pending rebuild...
Daily: Volt
Daily #2: '99 EVG ebike- STOLEN by PEDRO