I installed a LM1 Wideband O2 sensor on the racecar but the readings don't seem to be accurate. I haven't played with it much but I was trying to get the idle set down around .82 Lambda or so but I'm not having any luck. I can't get a reading under around 1.8 which is super duper lean according to the instructions. The meter does respond as it was 3 or 4 when I started. I was 4 turns out on all 4 idle adjusters and still 1.6-2 is the reading?? I'm thinking I may have put the sensor to close to the open end. I welded the bung into my collector extensions but its only a couple inches from the opening. I have the Quick Fuel Metering blocks on my Holley 950HP.

I'm thinking at idle the exhaust flow isn't constant enough and its getting free air mixed in there messing with the readings. Is that plausible? Can I change the sample rate it samples so fast its difficult to read.

The car seems to be running good - its not getting hot or anything so I don't really think its all that lean.

One other thing - is there an easy way to view the recordings on the meter itself or do I have to download it to the laptop?

In the past with an O2 sensor, I have had it rich enough to actually have the meter read the wrong way on gas. I was told it was the cooling effect of the fuel hitting the sensor. Leaned it out, and the readings came in. Weird, but I have really big injectors for the engine I run.

As for the E85, if your jetting is on par with what others are running and your fuel pressure and float settings are good and its running good, maybe its the placement of the sensor. Are you running full exhaust or open headers?

If your running open headers, you will need extensions to get a good reading at idle with no back pressure, if you can even get them at idle. Pretty tough to get a good idle reading without a little restriction. Had the same problem with mine when I pulled the exhaust to race it, and with efi, it can mess with your tune.

Could be a bad sensor.

Try running a free air calibration.

Thank Again Jim!!

Thats what I thought. I have some turnouts like that I've been wanting to install so maybe those will help get a good idle reading. The way the gauge was jumping around I figured it was nonsense.

My laptop doesn't have a serial port so maybe I'll use the camera to record the data the old fashioned way.

No racing this weekend says the weatherman so I'll have to wait until next weekend to try it.

Did you get a error code? The first time I used the LM1 the motor was real lean and the senser overheated and had to get a new one. In the instructions they say keep the O2 senser at the end of the headers between 12 and 3 position.Has to be located where no external air can get to it. Header leaks up stream will also efect the readings. If the readings are all over the place the senser is most likly bad.If I new what I knew now I would of not bought a wideband unit.They are very unforgiving as in the O2 units will burn out easly and at 50 bucks a wack that sucks.