Multiple CEL codes...

[jeffreys38]

I got a CEL on my '98 Outback Sport and it immediately started running rough. The codes it threw were P0103, P0170, and P1443. Any suggestions on where I should start my diagnosis?

[4Wheel]

P1440 Fuel Tank Pressure Control System Low Input ,,,,??.Any one familiar with this code?

PO103 One of three things to check:
1). The MAF may be disconnected, or a wiring connection may be bad
2). The MAF sensor may be damaged
3). The vehicle computer may be faulty (very rare)

Reset the code and see if it comes back.
The most probable cause is an air leak, bad connection at any of the intake joints after the MAF and before the throttle body. Inspect for any air leaks near the MAF sensor.

Check that the Mass Air Flow Sensor wiring is connected properly and that there are no broken / frayed wires.

Take the MAF out and clean it using a spray cleaner such as brake cleaner or electrical contact cleaner. Be gentle with the sensor.

Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information)
Replace the MAF sensor.


P0170 Fuel Trim Malfunction (Bank 1) I would leave this one until the other two have been remedied as it may be a sub-symptom of the other two malfunctions.