I don't know how to attach the scanned page but heres what needs to be done. The helms manual states if there is a DTC of p0172 (45) system too rich. Here are the propable causes.
fuel pressure clogged, stuck open
fuel return line clogged
fuel injector leaking
gasoline doesn't meet owners manual, (specified octane reading)
primary o2 sensor
MAP sensor
EGR
EVAP purge control solenoid valve leaking
Valve clearance.

Heres the procedure to check:
-Cheak fuel pressure. (you'll need access to some type of fuel pressure check gauges if not, you'll need to go to a shop.)
-if pressure is within specs D16y8 (38-46 psi with vacuum hose disconnected)
check primary o2 sensor.
-if not within specs-pressure too high-check fuel pressure regulator and return line. high pressure will cause rich conditions.
This is as far as you are capable of doing. the next steps will require you to have a scan tool.

I would recommend having the dealer diagnose the problem. They will hook up the scan tool and drive it in the condition that throws the MIL and take a snapshot at all the sensors. Thats the quick and easy way to look at all the sensors and figure out what is happening when the MIL comes on. The other route is you could go changine parts unless you have access to a scan tool.

I would assume the o2 sensor is dirty and not reading the oxygen level correctly.