ACCELR8

Will you get erroneous results if the front O2 is replaced with a wideband A/F meter? In other words, the front O2 is disconnected while logging AFR.

If the results will be affected, will the results read leaner or richer than the actual AFR when the O2 is connected? And will the results deviate a lot from the actual AFR when the O2 is connected?

Thanks,

Jim

red ws6 99

If you pull the front o2 sensor and install the wideband o2 sensor then you will definetly affect the idle and cruise afr. The car will go into open loop so it may be lean or rich depending on the all the settings in the car. You would be better off putting the wideband o2 sensor in one of the back o2 locations. It will not affect how the car runs or the wideband readings.

Gary

ACCELR8

The reason I asked the question is about a year ago a friend and I tuned the car with my MAFT and a wideband using the method discussed above. The final result was a 13.1 AFR, but I didn't think the car pulled like it should. Later I check the O2 readings at WOT with Atap; they were approximately 0.930 (I read that they should be between 0.890 to 0.900). This got me thinking that the wideband number was incorrect.

As for putting the wideband behind the cat, I thought I read on this forum that you always wanted the wideband installed in front of the cat. Although I could be wrong.

Thanks,

Jim

ACCELR8

Thanks Gary!

Any additional responses would be appreciated.

Thanks,

Jim

mikey

iTrader: (6)

The fuel trims will go to 0 and stay there so there will be no PCM control of the part throttle a/f via closed loop. The PCM will stay in open loop. This will not affect WOT tuning. So I suggest tuning for -trim cells with the the sensors in place and then do the WOT with the wideband afterwards. I removed my O2 sensors and tuned my car open loop because I run leaded race gas. I also locked my fuel trims in edit. The key is to get your VE table perfect so the trims don't need to do much. I'm working now on getting rid of the MAF all together

ACCELR8

Thanks for the reply Mikey

Based on the fact that you're the owner of Rapid Motorsports and you have a car that runs 9's , I'll go out on a limb and take a wild guess that you know what you talking about.

Thanks again, you definately answered my question.

Jim