Lean & Rich Exhaust

[SSTibet]

Folks,

I am pretty new to cars and I wonder what "rich exhaust" and "lean exhaust" mean? It is not that I have a problem as such, but I am just curious...

Thanks for any information.

 

[ShaneL]

The optimal Air/Fuel mix is 14.7 parts air to 1 part fuel.

In a Rich condition you are running with a greater than optimal ammount of fuel in proportion to air.

In a Lean condition you are running with a less than optimal ammount of fuel in proportion to air.

(hope i'm right )
-Shane

 

[SSTibet]

Shane...

You have become my personal tutor these days buddy... Thanks for all the assistance.

Hey, where are you in USA??? Male / Female??? Married? Kids?

 

[SSTibet]

O2 Sensor Question

Shane,

One last question, is it the 02 sensors in the car that measure the "lean / rich exhaust" condition? I am guessing that this could be the case since the O2 sensors should be measuring the amount of oxygen in the exhaust gas and throwing a signal to the ECM whether the "air to fuel" is right or otherwise.

What say you?

 

[ShaneL]

Yes the O2 sensors tell the computers to adjust the Air/Fuel mixture according to what they detect in the exhaust gasses. This is also why you may get better gas mileage when replacing the sensors because the new ones may respond faster and more accurately.


--------------------------


I'm down in Florence, SC.

Single with no kids and as you may be able to tell I am more of a night person.
:bar

 

[SSTibet]

I had my O2 sensors replaced last weekend . There are 3 sensors on the car; one on the driver side (before the cat) and 2 on the passanger side (one before and one after the cat). I had read somewhere in CAC that the O2 sensor on the passenger side, which is after the cat, does not emit any signals to the PCM, I replaced it anyways (I would replace this one with an O2 simulator if I could find one here - there was not any in the spare part shops ad )...

This new mechanic has the diagnostic computer and he told me that all 3 new sensors are now functioning - he had also checked them before. I also fueled up the car from a good gas station and put some injector cleaning compound in the gas. So far so good, no CES fault light or engine stumbling... Hope it goes on like this.