I have a 2002 ram 1500 automatic 2wd 4.7l that was recently rebuilt. my gas milage is 5 or 6 miles to the gallon. I put an analyzer on to see what codes it has . it says system pass. Is this common for the mpg to be so low? the engine has 98000 miles , but only 200 since the rebuild

 

Fuel pressure is too high, or, your O2 sensors are toast. Not an unusual occurrence after a rebuild. What do your fuel trims look like?

 

I know how to check the sensors, but how would I lower the fuel pressure.

 

I believe the regulator is in the fuel pump module, in the tank. Not adjustable..... It either works, or it don't.... Generally, the pump itself fails before anything else in there. I would be looking elsewhere.

 

Check the basics and you'll find the problem.
Is your tire size and gearing stock? Is speedometer calibrated for your setup?
Rec conduct spark plug analysis and compression test. The spark plugs will tell you what's going on inside of the engine.
Anything unusual with the engine recently? Overheat, codes?