Bad o2 sensor and the Apexi Power FC

[jamanrr]

hey guys, I think my fatty o2 sensor has kicked the bucket -- it will not above .2 volts or 200 mvs and is lazy barely moves --- I unpluged and the car ran better and idles good. I think this is why my car has not been running good as of late. I order one for 60 bucks and see if it will make the car idle better. Under WOT I am in closed loop and it does not matter but down low and at idle under small boost it runs like shit.

[jspaeth]

Depending on how well tuned the upper (vacuum) part of your fuel map is tuned, you could go in and turn off O2 feedback.....

I run my PFC with no O2 feedback whatsoever and it works great....I tuned all of the cells by datalogging and I get like 15.5 or so AFR under solid vacuum (maybe like 7-8 psi vacuum) tapering up to around 14.5 at like 2-3 psi of vacuum.

Then taper up to around 13.2-13.5 at 0 boost pressure...


Not sure if this is "right" or not, but those are the AFRs that I use and the car never knocks and gets amazing gas mileage.

[jamanrr]

Depending on how well tuned the upper (vacuum) part of your fuel map is tuned, you could go in and turn off O2 feedback.....

I run my PFC with no O2 feedback whatsoever and it works great....I tuned all of the cells by datalogging and I get like 15.5 or so AFR under solid vacuum (maybe like 7-8 psi vacuum) tapering up to around 14.5 at like 2-3 psi of vacuum.

Then taper up to around 13.2-13.5 at 0 boost pressure...


Not sure if this is "right" or not, but those are the AFRs that I use and the car never knocks and gets amazing gas mileage.

I already bought the O2 sensor 60 bucks not bad at all. I looked at the o2 sensor in my sensor settings and it was DEAD. warmed it up and never got above .45 volts and did not move around -- the car runs fine up top but under small loads and idling it is soooo rich that it sputters and back fires some. Not a hard replacement. Took a while to figure it out though especially without no MIL or CEL. Replaced plugs looked at a lot of things. I just am wondering if replacing the thermostat with silicone based sealant got into the engine some how ruining the O2 sensor? Of course it is 15 years old by now and has at least 100,000 + miles on it so I guess it was due.

[M1992]

Could you provide a dummy-proof description of how to turn off o2 feedback? I think it will help my car.

[kaoliu]

Could you provide a dummy-proof description of how to turn off o2 feedback? I think it will help my car.

From the top of my head...

Disable the "02 F/B Control" found within the "ETC" menu options under "Function Select".

[RB25GUY]

http://www.paulr33.com/powerfc-emulator/menu.html