Lean Condition

[ChevyTech]

So you are saying that its possible that the truck is running lean even thought the scanner shows rich/lean?

The code should not be getting set under the conditions when the scan tool can keep swinging rich & lean unless the ECM is failing. I doubt the ECM is failing.

The truck could be lean at some running condition, possibly the O2 wire is bare in a spot and touching ground, or air could be getting pumped in ahead of the O2 sensor in “closed loop” at times. The O2 sensor could also be the problem. A vacuum leak is a possibility, but it would need to be a fairly big leak.

When you get your meter connected to the O2 wire, if the O2 voltage is not swing above .5 volt at all, then carefully pour/squirt a little fuel in the TBI, and the voltage should go high. If it will not go high even when you pour/squirt fuel in, then it is time to replace the O2 sensor.

How often does it set the code 44?
What driving condition (up hill, freeway…) causes the code to get set/Light to come on?