Noticed my scan master O2 readings are very low (30-45) at idle and crusing. At WOT, reading goes to zero. Just reving up in driveway will cause reading to go to zero. Fuel pressure at idle is 42psi and WOT is 68 psi at 25 psi turbo boost. Car runs strong at WOT with no retard. No error codes are showing up on the scan master. The O2 sensor is heated and has been in the car about 3 years. Do you think the sensor is bad? See signature for set up. Thanks.
Do I have a bad O2 sensor?
- Thread starter jghall6
- Start date
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
They can go bad....I'd check elec connections first. What's the cross counts look like?
Cross counts are stuck on 12 from cold start up to fully wamed up crusing at 60 mph. Did not change even at WOT.
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
Somethings screwy...maybe try another one and see
SCOOBY DOO
BASED CANADIAN PATRIOT!!
- Joined
- Feb 18, 2007
CC's should be moving fairly rapidly.
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
Should jump in increments of ten or so
Cross counts will only move during closed loop cruise conditions. They will not move when in open loop like WOT, or at idle, if you have an open loop idle chip which I suspect you do.
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
Good catch ...its a TT chip so bet its open loop idle.
Thanks. I will replace the O2 sensor today. Does alcohol injection cause a O2 sensor go bad? I use a 50/50 mix denatured alcohol and water.
New O2 sensor works great. Scan master reading are good now. Thanks.
My car is doing something similar based on my powerlogger readings. I just wondered what you replaced your 02 with. Rockauto has the stock AFS21 for 14$. How much are the heated? Why are they much better? and do I have to do anyone extra install to hook one up? Thanks
SCOOBY DOO
BASED CANADIAN PATRIOT!!
- Joined
- Feb 18, 2007
Throw a Denso in...and you're good to go.
The heated O2 sensors are used because they last longer when you use leaded race fuel. I had the heated O2 sensor because I used leaded race fuel before I switched to alcohol injection. I replaced it with an OEM sensor by NTK from advance auto for $20.00. I think the heated sensors are around $90 -$100 but there is no need to have one unless you are running leaded race fuel. The heated sensor that I replaced had a wiring harness that pluged into the connectors without any modifications. I think I got it from Kirbans Performance.
