P174 trouble code rich fuel mixture bank 1.

P0174?

Too lean, Bank 2

This right?

If so,

Possibilities are a dirty air filter/ or you are using a K&N (or similar) air filter that the oil on it is getting on the MAF Sensor.

A vacuum leak leak on a hose (or even anywhere)

Try this, this is the most common fix before you mess with anything else, if you will remove the MAF sensor, clean it well with brake cleaner, allow it to dry, reinstall it.

Let us know if this fixes you!

The Medic

Since this lean code is only for one bank of the engine, it's is highly unlikely to be caused by a MAF. Even a vacuum leak would have to be somewhere that heavily favored that bank of the engine. An exhaust leak on that bank is a possibility also as that would introduce air to the 0/2 sensor. It could be just an 0/2 sensor incapable of reading rich. These things can be tested by inducing a rich mixture while monitoring the 0/2 reading on that side and doing a smoke test.