P0174 Error Code

Check engine light on and the error code "P0174- System Too Lean". I tried to clean the MAF, and temporarily the light went off. Now the light is still on and I get about 8 mpg around town!

Now the rear brakes squel when I put it into Reverse to leave the driveway in the mornings. Could the brakes be restricting the wheels from turning?

Someone told me I should take it to Ford for a Diagnostic, but I was burnt once from them and would just about drive it into the river before I do that. Any ideas?

Thanks, Tony