2002 bogging down when stopped

I have a 2002 Suburban with 63K miles. The service engine light has been coming on and off for about two months. Thought is was the gas cap. It has been running rougher and rougher when idling, and then this week it started to bog down when at a stop light pretty bad to the point it almost stalls. I think it has been sucking gas more than normal, and as a rule the wife runs it down to fumes before filling it up.

I took it to AutoZone since the engine light is having one of its “on” times and the code reader stated “Bank 1, system running lean” and “Bank 2, system running lean”.

I am not an expert or artesian mechanic by any means, more a journeyman, and am looking for some advice on what to check. The auto zone guy said it could be about anything. Thanks, and I hope he has a nice day in high school tomorrow . . . .

My initial assumptions are:
--Banks means my fuel injector banks not O2 banks.
--“System running lean” could mean either:
its truly running lean and that’s why its bogging done or
the system only “thinks” its running lean, so its adding gas and that’s
why it’s bogging down.


Things I will start to trouble shoot this weekend, any additional suggestion are welcome:

-- Fuel filter under the drivers seat was replaced about 2 years ago I will replace this Friday. Choked fuel line?

-Do some blocking and tackling: check hoses, air filter lockdown, and visual survey of the exhaust and cat. Yes, I should have done this first but its been cold in Chicago and I keep it outside.

--Check the mass air, plugs, and fuel regulator?

--Not sure on the oxygen sensors, it may be worth while to swap out anyway based on mileage versus pay a shop $150 to run diagnostics to tell me the same.

--others?

Thx, Drew

Check fuel pressure first, then look at possible vacuum leaks, the engine is so lean the pcm is at it's limit to correct the mixture. BTW running chronically low on gas will damage the fuel pump.

Thnaks maxwedge, I will take a look.

Check fuel pressure first, then look at possible vacuum leaks, the engine is so lean the pcm is at it's limit to correct the mixture. BTW running chronically low on gas will damage the fuel pump.

Sounds like a plugged filter, 2 years and running it low on fuel will make it suck the crud in the tank up more often. When you pull the filter see if you can blow through it, it should have very little restriction.

Update:

I did the best I could on my own to no avail. It was still running lean. I took it to the local shop and it turns out my air intake gasket is sucking air. I am replacing it with a flex fuel gasket so I don't have to go through this again. Thanks for the help and suggestions.

Also I am trying educate the wife on gas tank etiquette, she's a late model '68 and hard to recondition . . . . .

Update:

I did the best I could on my own to no avail. It was still running lean. I took it to the local shop and it turns out my air intake gasket is sucking air. I am replacing it with a flex fuel gasket so I don't have to go through this again. Thanks for the help and suggestions.

Also I am trying educate the wife on gas tank etiquette, she's a late model '68 and hard to recondition . . . . .
What or where is this air intake gasket, just curious, that nomenclature is not familiar?