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Ambrose 4/3/2010

2002 Pontiac Sunfire SE 4 Cyl 2.2L


Scanned, code is P440, evaporative emission system, no other information. Looking for recommendatins?

Engine light ON. Used scanner to test 02 Sensor, rich to lean threshold is .555 and lean to rich threshold is .590. Doesn't help me much, don't know what to do with it. Engine runs fine, for the last year, slight oil leak starting on intake manifold gasket.

2 Answers


Chiekotz 7/1/2010

So oil made it to the intake manifold gasket, you have bad piston rings. Whats the color of your smoke? Blue?


Bobby 7/1/2010

P0440- Evaporative Emission Control System Malfunction

The Evap system is part of the fuel system it runs a self diagnostic check by testing for vacuum and purge rate of the evap system. A common cause of this is actually putting your gas cap on wrong! so start there make sure the cap clicks on correctly .Also inspect the gas cap make sure the gasket isn't missing or cracked so the fuel system seals properly. Last it could be the cap itself is defective. The other causes could be a leak in the system caused by a cracked hose or the EVAP canister being broken. Or the malfunction can relate to no signal fro the EVAP sensors. First thing most mechanics do with this code is clear the code remove and retighten the gas cap and then drive the car for a while and see if the code comes back. if it comes back then you'll need to diagnose the evap system more, startig with the gas cap.


Clug 8/7/2010

I am having the same problem. Check engine light on and code reads Evap. Checked gas cap and cleared code. Light came back on after driving several times. Replaced gas cap with a new one and cleared code. Light came on again. What else could be wrong?

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