O2 bank sensor question
Thread Starter
Navigator
Joined: Jan 2022
Posts: 9
Likes: 0
From: Athens Al
O2 bank sensor question
Thanks ahead of time. I took a reading from my ODB port to get readings from my O2 sensors. And I understand the banks and sensor locations, but my hand held said I had 4 banks and the odd thing is, does this car not just have bank 1 and 2. Because bank 1 had numbers, bank 2 said NA and bank 3 had numbers and the bank 4 said NA. And from what I know bank 1 is drivers and bank 2 is passenger. So why does this bank 3 have numbers? Just odd I thought, or am I missing something... reason for the readings is a friend said they said they could really smell the awful CAT and fuel smell. And I just want to make sure sensors were working fine within range, which they are.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,615
Likes: 4,062
From: Cape Coral, Florida
Are you looking at your car or your friends which is not a Corvette ???…Bank 1 is driver side and bank 2 is passenger side…there are 4 O2 sensors…2 upstream of the cats and 2 downstream of the cats…the upstream O2 sensors control the ECM fueling strategy and the downstreams monitor the cats…the upstreams are supposed to oscillate between 200-800 mv’s and the downstreams are steady around 700mv”s or so….these code readers are basically useless other than clearing codes…they should be labeled B1S1, B1S2, B2S1 and B2S2…have no idea why you are having a bank 3 showing numbers ??…if you have a bad upstream sensor that is “stuck” low around 100-200mv the ECM thinks the engine is running lean and will schedule more fuel and your car will run rich…smelly exhaust !!
Last edited by C5 Diag; Mar 26, 2022 at 07:02 PM.
Team Owner
Joined: Jul 2004
Posts: 28,472
Likes: 3,290
From: Hartford WI
Are you looking at your car or your friends which is not a Corvette ???…Bank 1 is driver side and bank 2 is passenger side…there are 4 O2 sensors…2 upstream of the cats and 2 downstream of the cats…the upstream O2 sensors control the ECM fueling strategy and the downstreams monitor the cats…the upstreams are supposed to oscillate between 200-800 mv’s and the downstreams are steady around 700mv”s or so….these code readers are basically useless other than clearing codes…they should be labeled B1S1, B1S2, B2S1 and B2S2…have no idea why you are having a bank 3 showing numbers ??…if you have a bad upstream sensor that is “stuck” low around 100-200mv the ECM thinks the engine is running lean and will schedule more fuel and your car will run rich…smelly exhaust !!
