I'm not sure how the fuel pump would cause a small EVAP leak.
Do me a favor. Check the fuel filler tube between the fuel tank and the side of the bed for rust. Also, and don't laugh, check to see if there is any corrosion or rust on the filler where the fuel cap is attached.
Here is the diagnostic flow chart for the code. It does require a scan tool that can actuate components. The attached pics correlate with these directions.
1999 Dodge or Ram Truck RAM 1500 Truck 4WD V8-5.9L VIN Z LDC
Vehicle ALL Diagnostic Trouble Codes ( DTC ) Testing and Inspection P Code Charts P0442
Tests 846 - 848
see pic 1
Tests 849 - 850
see pic 2
P-0442 EVAP LEAK MONITOR SMALL LEAK DETECTED
Immediately after a cold start, with ambient temperature between 40 degrees F and 90 degrees F and coolant temperature within 10 degrees F of ambient temperature.
If there is a leak larger than 0.040" and smaller than 0.080" in the evaporative system.
- Evap system hoses or wiring damaged
- Evap system component leaking
- Leak detection pump leaking
- Evap leak monitor small or large does not reoccur
Let me know what you find or if you have other questions.
Images (Click to enlarge)
Saturday, October 31st, 2020 AT 8:29 PM