My dodge 2003 Ram 1500 5.7 HEMI will not stay ideling. When I push on the gas the engine will rev up and stay running, but surges up and down. It seems like a intake leak. But I cant seem to find one. The code that comes up is P0172 (bank 1 too lean). I have cleaned the throttle body and checked all the wiring connectors. No wires disconnected. I do not have a tester to run diagnostics. Has any one seen this same issue with their 5.7HEMI?
Will not stay running. Fault code P0172 on 2003 Dodge Ram 1500
by Visitor in Smithfield, PA on May 10, 2010
ANSWER by Visitor on May 12, 2010
ANSWER by Visitor on July 21, 2010
YES IT WAS A IDOL SENSOR
ANSWER by lude22r on July 22, 2012
P0172 is :system too rich (bank 1). This is usually caused by a restricted/clogged air intake filter. Manifold absolute pressure sensor, throttle position sensor, engine coolant temperature sensor, open thermostat, leaking fuel injectors, failing fuel pressure regulator, failing oxygen sensors.