I have a Auto Meter air/fuel guage and a Apexi Timer that gives me a digital readout of air/fuel ratio. The Auto meter basicly stays in the last 3-4 yellow bars when maintaining a constant cruising speed and bounces around the rest of the time. The Apexi reads in 14-15 range from the when the Auto Meter is between the 3-4 red bars up to the last (10th) yellow bar. When the Auto Meter is at the 2nd red bar or below the Apexi ranges between 15-20 and when in the 4 green bar range it reads betwen 14-10. Does this sound correct it's new ground for me but I like the Apexi readout, is it more accurate? I heard the Auto Meter isn't real precise, is this because of the guage or the stock o2 sensor?

 

You need a "wideband" o2 readout. Tapping in the stock oxy sensor will not give you very accurate information since the sensors are calibrated concerned with mainly maintaining a stoich mixture. Some people think the common air/fuel gauges like the autometer are very usefull. I don't agree even though I've had one in most of my cars, I suggest using it only to tell when something is wrong, and not to see if things are correctly tuned.
Ahmet

 

Yes, narrowband lambda readout is pretty useless except for setting stochiometric A/F ratio at idle. Dont use a stock O2 sensor to tune your car!

 

Any idea on the cost of swithing to a wideband and difficulty of install? Would I need this before installing a plug and play such as the UTech?

 

Good wideband O2 with LCD is from $700, a good one $1000.

 

They aern't accurate at all, mine ended up breaking after about 6 months