how can you tell if your running lean?

 

Pull your spark plugs, look at the color.

 

What is a wideband oxygen sensor?
A wideband oxygen sensor is a sensor which allows you to monitor parts air to fuel. Most people have the preconception that a basic autometer air/fuel guage using the stock oxygen sensor in their vehicle will give them all the information they need about being in a lean or rich condition. This information is false, the factory narrowband oxygen sensor will not provide you with an accurate reading because the oxygen sensor is a narrowband sensor which does not have a wide enough of a range to accurately sense air/fuel mixtures needed to properly tune a vehicle. The purchase of a wideband oxygen sensor is not required due to the fact that almost every tuner provides one with his services etc.

 

lol^