bigbudha

hi i have 2003 e320 with 69k mile check engine came on and i checked the code.
p0123 p0442 any help will be great.

Plutoe

Without a VIN I am somewhat handicapped as I could not find an OBDII cross reference for P0123 with an E320 ME-SFI fuel injection system(2.8).

However P0442 relates to a minor leak in the fuel tank vapor purge system. Assuming you do not have a dash message regarding your filler cap, the fault concerns the purge control valve is leaking(not fuel), but fumes.

How old is your filler cap and does it close tightly----if it does than it's the valve


edit--I checked with the VIN---still no reference to an OBDII fault P0123---all other ok!!

bigbudha

Pultoe,
thanks my vin#wdbuf65j23a153156.
i checked the gas cap the plastic string that holds the cap was trapped between the cap and the tank.

ozusa

P0123 is a generic code: Throttle position or pedal position sensor/switch circuit, high input.

Now what does that actually mean? It may mean you have a bad throttle position sensor (and it may not). If your code reader is more than just a simple reader, it may be able to show you the behavior of the TP. The thing to look for is a steady transition (%) in the TP as you press the throttle through its range with the engine running. Not a jerky change in the %. A smooth press of your foot should result in a smooth change in %.

As for symptoms, you could get transmission or other issues with a bad TP sensor. If you have no symptoms of that, perhaps you could clear the code and see if it returns.

bigbudha

thanks ozusa