is there an easy way to tell if i am running air/ fuel rich or lean without getting a air to fuel ratio gauge in my car? there must be a way i just don't know about. and whats the easiest way to correct either of those? i figure you can just adjust how much fuel you are using right?

 

You can tell by the smell of the exhaust usually. Is your car carbed or fuel injected?

 

fuel injected

 

You need to data log and check out your BML's. That is the only accurate way to tell.

 

how do i go about doing that?
i have heard that you can tell by the smell of the exhaust, how exactly does that work. i know it is probably not that accurate but i was just wondering how that worked.thanks guys

 

Well if your car has a cat than it is not very accurate. You car can still run rich even though it smells fine with a cat. That means the cat is doing its job and that you aren't so rich that it is not keeping up.

 

what does it smell like if its running rich and i don't have a cat? like gas maybe?

 

Yup

 

If its rich w/o a cat you will know when you start clawing at your eyes b/c they burn from the raw fuel coming out!!!

 

There is another method, but it is subject to the same variability and innaccuracy as the ECM data logger method. If the O² is being "fooled" by an air leak into the exhaust, or is weak or contaminated, reading data drom the ECM is useless. The only positive method is with a separate wideband oxygen sensor, either installed in the exhaust stream or as part of an exhaust gas analyzer.

If you have confidence in the integrity of your O² sensor, you can invoke the Field Service Mode through the ALDL, and reveal whether the ECM is trying to correct for a lean or rich condition. There is no means to quantify the degree of rich or lean exhaust gas, just to tell whther it is rich or lean.

 

Your engine should be changing from slightly rich to slightly lean and back again. If it's not your O2 sensor is probably bad. I have an Auto xray scanner that tells me if my car is doing this. It's kind of an expensive tool ($175.00), but it does a lot other tests as well and it works on other GM cars and trucks up to 1994. I wouldn't want to work on my car without it.