Hi,

This was copied from a table in frequent asks questions.

https://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

2-3-2* Fuel trim (lambda control) too lean or too rich at idle }If too rich: high fuel press., leaking injector } various driving problems Fuel trim (lambda control) too lean at idle Oxygen sensor

The trouble with this code it is so generic that it’s almost worthless.
The main thing is the idle mixture is too lean and thus is most likely from a hose leak.
A vacuum hose or the snorkel tube might have a TINY crack. The snorkel tube is very susceptible to these down in the volutes or a hole rubbed into the tops.
I mentioned that as being is behind the AMM and goes to the throttle.
Try to keep the sides of the tube from rubbing anything like a strut tower.
Everything has to be air tight behind the Air Mass Meter or Manifold Absolute Pressure sensor (MAP)

The AMM is likely to be a Bosch unit and will say so, on the square part facing the engine.
The most common number is a Bosch number ending in 016 on last models of the 240’s.
The 700 series were being produced at the same time and several parts were interchangeable despite every effort to screw things up!
If it’s a rebuilt one it can have another name with a sticker saying “injection labs” that is a common rebuilder.
There is no way to test these but you should pull the connector and give the pins inside it a gander for any tiny amounts of corrosion.
Look to see that they are all up at the top and even as to show that they are properly seated in their respective holes.
Just removing it and disturbing them creates a cleaning action and might temporarily cause a fix. I have had that happen on my 240’s.

As far as an oxygen sensor goes it doesn’t usually cause a stall right when you touch the gas pedal.
It’s not that fast to react. So I’m saying it throttle related and the cleaning of the throttle body can only help!
The throttle switch has to click just as the throttle opens from being a “completely closed plate” inside!
This gives the computer a heads up that conditions are about to change.
The is a transition moment to step up power and the fuel to keep it rich enough.
All idle AIR must go through the Idle Air Control valve. IAC

If the engine is running or hitting smoothly and starting quickly there is no need to suspect ignition or fuel pumps or the AMM at this time.

Squaring away the air intake, with the gas pedal movement, is the heads up and you have done good!

I definitely understand why the kids in the neighborhood or in the family want to pick your brains and skills you have acquired!
I get that quite regularly on lots of things household running related.
Face Time gets used with my in-laws that are just handy enough to handle some tools and are adventurous!

It come with the territory of being socially capable!
(:-)

Phil