I have a AWD V70XC. 1999. In Aug/04 the "engine " warning light came on. Th e computer Dx said the throttle body linkage and front O2 sensor were defective. Both were replaced. The front O2 sensor had been replaced 12 months prior to that and 12 months prior to that ( 3 times in 24 months. At 1000 km after most recent replacement Aug/04 the warning light (engine) came on again. It was retested at the dealer computer and they felt O2 sensor adaptor cable was defective and replaced it and a "warranty" O2 sensor.

About 400 km. later the light is back on again. The car contiues to drive perfectly and always has.
The costs are mounting to try to turn a light off.

This is now the 4th O2 sensors in26 months 2 within the last 2 months.
Needless to say I do not think the dealer understands if there is a problem or how to correct it.

Has anyone had this experience or any idea why this is happening and how it could be fixed?
Doug.