my check engine light came on I had it checked and the code was p0440 is this something I can fix myself or do I need a mechanic?


Asked by Sep 25, 2014 at 05:12 PM about the 2002 GMC Envoy 4 Dr SLE 4WD SUV

Question type: Maintenance & Repair

7 Answers


This is a emission control malfucntion,could be clogged vacume canister,or just a sensor,best left to pro to fix,this.

1 out of 1 people think this is helpful.

This trouble code is telling us that the computer has detected a large leak in the EVAP system. The EVAP system recirculates gasoline fumes back to the engine to be burned up instead of being released into the air. First thing to do is check your gas cap. Make sure it's on tight. A loose gas cap will cause this trouble code. If your Envoy is running ok and the gas cap was on tight replace the gas cap. A leaking gas cap will cause this trouble code when the vehicle is running fine. Once you've done that, drive normally for about a week but keep the gas tank between 3/4 and 1/4 full. No more and no less. This will allow the computer to run the necessary tests on the system and determine if it's ok and turn off the check engine light. If the vehicle is not running right look for a disconnected or damaged vacuum hose under the hood. This will cause this trouble code and a poorly running engine. HTH. -Jim

6 out of 6 people think this is helpful.
Bernell Pruitt

I had a test done and 4 codes came up what should I done

2 out of 2 people think this is helpful.
Bernell Pruitt

I replaced the gas cap now it might be the upper lower oxgen senor. Could that be the problem.

Bernell Pruitt

I had a test done and 4 codes came up what should I done Could you call me I would like to talk 716 605 4428

3 out of 3 people think this is helpful.
Bernell Pruitt

I would like to talk to you. 716 605 4428


When i did the obd ll test came up po440 I replaced the valve under the hood n ran fine after There is a video on utube showing how to replace the sensor valve Its located on the right side of your engine Has two ends of which hoses are attached n is black This is for the 2002 envoys

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