2002 2.3 check engine light says "lean"

[GT350HR]

Did the smoke test and no cracked hoses or smoke anywhere. Cleaned ( twice) the mass air sensor.. Check light only comes on ( after a reset) at IDLE , never under power or decell. When it does come on the idle hunts a bit indicating it is not happy. ANY suggestions welcomed and will be tried. I don't want to do a wholesale parts change!
Thank you in advance,
randy

 

[adsm08]

If there is an unmetered air leak it will represent a much larger portion of the total air intake at idle than it will under power, and on an engine braking decal the computer has cut fuel and is expecting to see a super lean condition, so it won't flag that as a problem.

If you have access to a good scanner record your short and long term fuel trims at idle and at 2500 RPM, or where ever your rev limiter will cut you off, which ever is lower.

Then subtract the idle short term from the idle long term, and the same with the off idle numbers. The subtract the lower result from the higher result. If the total change is more than 15 points you have an air leak, if it is less than 15 you have a bad MAF sensor.