It is my husbands 1996 850 turbo SW, I had bought a Grupon oil change and maintenance inspection. He tested it and two codes p0172 and p0440, whatever that means. I don't drive the car, but I know it has been neglected due to his age. The car is also leaking oil from valve cover gasket. Drive axle boot compromised. Might be too costly for an old car. Which is a safty issue?....Laila

p0120 throttle position sensor/switch
p0172 system to rich bank 1
p0440 Evaporative Emissions failure

code p 0440 refers to evaporative emission (EVAP) system---malfunction===causes ---hose connections ---intake leak---EVAP canister purge valve
probably the purge valve needs replacing

code p 0172 refers to system too lean, bank 1===causes --intake blocked , EVAP canister purge valve ---fuel pressure ---EGR system---injector/s HO2S
you will notice that the purge valve is in both codes and it also affects the fuel pressure by not venting the tank correctly
That will account for the fuel pressure problem
I would seek advice from an accredited service specialist that works on your type of car but I would be paying attention to the common fault ( purge valve) before any thing else

You need a repair shop to drive the vehicle with a professional
scan tool, for at least 25 miles

That way all the Emissions Monitors will run clear

If you fail to do that,your guaranteed to fail inspection

If any codes come back,then the vehicle has to be component
test & repaired

It sounds as though there was some pushing & poking, done by
I assume, a shop & parts changed,tested or in need of replacing,
who knows

You also will have freeze frame data at the time the codes are set,
to help with the diagnoses,IF-- you have a good shop to work on it,
so far that doesn't appear to be the case

I don't buy your hopeful rational --IF-- the oil has not been changed
(often)over the life of the motor,wrong oil used or the cam actuators
have failed,as is sort of where all this conversation has gone or
explained to you

If the cam timing is not correct,then yes, the oxygen sensor codes
may set- BUT- I don't buy the fact they go away & never come back

We could be here a long time,so I suggest you keep your line of
questions going at a repair shop. Their not wrong or far off,you just
need to understand how things work together in a motor or maybe
not play well with other parts under certain conditions

you can look this obd2 trouble code table.
for p0440, you can try this:

Remove and reinstall the gas cap, clear the code, and drive for a day and see if the codes come back.

Inspect the EVAP system for cuts/holes in tubes/hoses

Inspect for damaged or disconnected hoses around the Evap purge solenoid

Check and/or replace the sensor

Check and/or replace the purge valve

Have a professional use a smoke machine to detect leaks

This indicates that a part of the EVAP control system is no longer fuctioning correctly.
A code P0440 could mean one or more of the following has happened:

• The gas cap is not installed or working properly.
• The purge solenoid has failed.
• The canister is plugged and not working properly.
• -----------

Evap purge solenoid should be clean and tight.Also inspect for damaged or disconnected hoses around the Evap purge solenoid. -------------- This will help.Thanks.Helpmech.

Causes A code P0440 could mean one or more of the following has happened:

• The gas cap is not installed or working properly
• The purge solenoid has failed
• The canister is plugged and not working properly

Possible Solutions With a P0440 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try:

• Remove and reinstall the gas cap, clear the code, and drive for a day and see if the codes come back.
• Inspect the EVAP system for cuts/holes in tubes/hoses
• Inspect for damaged or disconnected hoses around the Evap purge solenoid
• Check and/or replace the sensor
• Check and/or replace the purge valve
• Have a professional use a smoke machine to detect leaks

what were the specific inspection details like Co, 02, CO2 and NOx readings?

furthermore, have you done any maintenance like fuel filter, oil change and spark plugs?

P0440- EVAP Emission Control Sys Malfunction

Something unspecified is wrong with the evaporative emission system. Check vac lines. Could be a loose electrical connection. This code has a very vague description.


P0302- Cyl 2 misfire

Has the car had a tune up in the past few years? Check plugs and wires, test for spark. Maybe a compression test. This issue may cause the next code.


P0172- Fuel trim Bank 1 , too rich

I would clear up the misfire first, then this code might go away.


P1613- MIL Call-up circuit open/Short to B+

Check the wiring under & behind the dash and instrument cluster. There apparently is a wiring issue, or the dash itself is shorted

change oil and filter will help /replace spark plugs too

Check if there smoke from the exhaust if its high then there is change oil getting burn in engine ...

Good luck..