What are the side effects of running the car without a 02 sensor connected to the PFC.

Like anything serious. Bad Gas Mileage?

 

Your ECU will not have an A/F reading so you will most likely pop your motor.

 

actually thats not true. The stock ecu doesnt even read from the o2 sensor after like 3k rpms ( if im not mistaken on the rpms) some people say their cars run better with it out.

 

That is what I figured too RX.

I just need a bit of input as why my gauge isn't working correctly when its connected to the ecu.

I believe after a certain RPM, it will run on the fuel maps and no longer rely on the o2 sensor.

I have a gauge and when I connect it, it shows it runs rich so I don't believe I can detonate the motor while its running rich, plus if it does run lean, I will know about it.

 

WEll, if your speaking of an AF gauge they are next to worthless unless they are based off a wideband o2. However they can tell you if your oxygen sesnor is on its way out if they start to act weird.

I just noticed your running with thePFC. There is a setting on there to run based off the 02 sensor or not. Im not familiar with it yet as I dont getm y pfc for a day or two

 

You'll get a little worse gas mileage on light throttle and idle.. but it won't surge any more (good thing). I have run without it for several years now. I hated the light-throttle surging. Just turn it off in the commander options menu.

 

Yeah I unhooked mine over a year ago. It won't hurt anything

 

really?! WOW, I woulda thought disconnecting the 02 sensor would be bad......hmmmmmm, that's kinda weird. So what do you do, disconnect it at the harness and leave it in the bung of the downpipe?

 

Very, very wrong.

Just turn off the O2 sensor feedback option on the PFC commander. You're done. The car will read off of the maps for all cruise and idle conditions instead of running off of the o2 sensor. Lots of people do it.

 

I'm just having a hard time getting my A/F ratio to work. =P

 

Actually it is much easier to tune the afr without the o2 feedback on. I turn mine off and tune the afr in the cruising cells and the car is much smoother with better gas mileage.

When it is on it bounces from too lean to too rich constantly and the car surges unless I add a ton of fuel,=waste of gas. You do not need to worry about popping your motor when you turn o2 feedback control off. According to most from the datalogit forum just turn it off if you have removed your air pump.

 

Anyone else have experience or input on this?
I'm thinking about running my new setup like this with only a single bung further down the dp for a wideband.
Thoughts and opinions?

 

I have disabled mine for the last year...no difference as far as I can see. I have also seen several people mount their widebands in that stock spot permanently. In fact when I got my car tuned at KDR that is where he put his wideband O2 sensor. I just use my O2 sensor as a place holder there and put the wideband on every now and then when I get time to tune a bit more.

Shawn

 

I dont know if you'll have to bother with emissions, but you may have a complicated time passing a dyno-type test without closed loop working. I'd put a bung up by the turbo and if you don't use it for the stock O2, at least you'll have a spot for an EGT sensor..

 

Emissions at an idel might fail. I put a High output 5.0 in my CJ7 and thought I would run without the O2 and it fail at an idel, after putting them in it passed.