am I running super rich ?

[jimberg]

HAITHAM,

Chris, of course, is absolutely right, but I thought I would use this opportunity to explain the rich/lean gauge a little.

Our cars use narrow band oxygen sensors that can really only accurately measure near stoichiometric (14.7:1) air/fuel ratios. This is why there is a closed-loop and open-loop control mode. If we had wide band oxygen sensors that could accurately measure air/fuel ratios on the rich end (13:1) or richer, then our computers could always run in closed-loop control mode and give us better performance by giving us more precise fuel management.

Instead, the computer just uses some lookup tables based on MAF, ACT, ECT, and BAP/MAP(if SD) reading to get us in the ballpark of 13:1 at WOT. Since 13:1 is way outside of your oxygen sensor's range, your gauge will just peg at rich. You should be concerned when you are at WOT and your gauge isn't reading rich. In that case, you're running dangerously lean and could potentially damage your engine.

I don't actually have a gauge, but do you ever watch it when you startup in the morning? It should be pegged at rich, and then when the car gets to operating temperature, it should start bouncing back and forth between lean and rich. When you see it start to do this, you are in closed-loop control mode.