Downstream O2 sensor looks like someone shot it... - SRT Forums

ziggo0 · 07-02-2008, 10:22 AM

...so I've been trying to figure out my messed up idle issue...13 ~ 15 vac, pulsing at idle...I managed to get out my down stream O2 sensor just to investigate while installing my Wideband...it appears to be damaged? Could this affect idle? It looks like someone shot it with a pellet gun for shits and giggles.

thepowertowin · 07-02-2008, 10:24 AM

The downstream does have the ability to change the upstream goal voltage if it's bad. So yeah, if the upstream goal voltage is something different (perhaps lower) then it could run your car too lean at idle and give you a lean fluctuation.

ziggo0 · 07-02-2008, 10:41 AM

According to my wideband, my A/F at idle bounces inbetween 13.9 & 15.8? I know that is NOT NORMAL.

thepowertowin · 07-02-2008, 10:47 AM

If you can get a scan tool to read upstream goal voltage, that might help you, but most likely you just want to get that downstream o2 replaced before you do any more diag anyways.