98 5.7

1998 Chevrolet Tahoe • V8 AWD Automatic • 176,399 miles

My truck is burning gas to fast an if I am just sitting there fumes smell start coming into my truck if I pull of slow it has a***** in it while riding slow. I change mass airflow sensor, all 02 sensors spark plugs and the throttle position sensor, because that was the codes that came up, but now this, can you help me out please.
August 21, 2011.

Probable causes of an engine running rich are as follows: 1. Excessive fuel pressure can be cause by restricted fuel return line
2. Defective Oxygen Sensors.
3. Leaking injectors and fuel pressure regulator.
4. Coolant temperature sensor out of calibration.
5. Restricted air intake system.

Aug 21, 2011.