hi all , well the other day my oxygen sensor went belly up ,so today i changed it with the exact same as i took of , well since i changed it the revs are going mental , sitting still the revs go from 1000 down to 400 maybe 500 then back up , and when im driving it revs up and down itself , its a v70 2001 2.4 auto , plugged in vida and there are no codes ,so im at a lose , everything works fine with nackered one on oly prob is mil lights on , please please need help

 

If the light is on, there are codes

 

no light on ,and no codes

 

I wasn't quite sure what " everything works fine with nackered one on oly prob is mil lights on " meant... I assumed wrong.

 

Well I've put the old one in till I can digger out what's going on ,its strange though my car runs fine with old one in ,just Mil light on and message on dash ,,,,,just can't figure out why it runs like a bag of spanners with new one on ,,,,

 

V70, what led you to believe the O2 sensor was at fault in the first place? Sometimes the OBD codes suggest the O2 sensor is out of range - meaning it can't compensate enough - usually due to some other fault. That's not to say your sensor is bad. My suggesting is to check for vacuum leaks to start since they can trigger seemingly unrelated codes. I'd also like to know what the mil light is... is that referring to something on the VIDA or on the car's dashboard?