Help me with car engine obd car codes?

I own a 1998 Ford Contour Sport V6 engine. It has 52,354 original miles. But I'm getting a code it's P0174 says bank 2 too lean. ( is that due to one thing or multiple things)? Also B1600 Anti theft module ignition key transponder And the last one is B1601 signal not received. I had someone do the OBD thing to my car and he wrote this all done in paper. I included a photo with the original paper he gave me

I would say most likely a leak at the intake manifold gasket.

A mechanic can read the engine data with their $3000 scan tool. The voltages of all the sensors helps determine if the MAF sensor is bad. The 02 sensor voltages and switching times are also suspect. You check the 02 sensor voltages to make sure they are in spec. Too lean does not mean an 02 sensor is bad.
There's always a change the intake manifold has a vacuum leak. Check for broken vacuum hoses and cracks in the hoses.
To check for intake gasket leaks you spray carb cleaner at the bottom intake manifold gasket area to see if the idle increases.

The OBD (On Board Diagnostic) codes mean NOTHING if you don't have the knowledge to understand what is causing those codes to appear. The ONLY reason that auto parts stores give free access to OBD readers is so they can sell you stuff that you probably don't need. If you think your car is having problems, take it to a REAL mechanic and pay to have it done right the first time.

P0171 on a Ford is most often caused by a vacuum leak at the intake manifold. Unmetered air is getting into the engine.