I just picked up a used 2002 Quad Cab 4.7L 4x4 SB truck w/ 36,000 miles and love it. When I bought it the guy had to have smog certificate (CA) done for selling. He took it in and it failed due to a small leak in the gas cap (dealer thought this was the problem). The gas cap was replaced and it passed 2 days later. I bought it and have driven it for the past 4 days with no problems. Last night the check engine light came on and I searched this forum and my truck pulled code P0442 "Evaporative Emission Control System Leak Detected (small leak)". I have tried taking the gas cap off and reinstalling it with 4 clicks to no result. I have only filled it once with gas and made sure to click the cap 3-4 times. Does anyone have any suggestions, or should I just wait it out to see if the light goes off?

 

Run to Auto Zone or your local garage and have the code cleared. See if the light comes back on. If the truck is running okay, you can leave it for a while. Eventually you may want to find the problem. The check engine light will come on for some really minute problems sometimes, but if you are like me, you want everything right all the time.

 

The tech said it is most likely fuel cap related. He advised me to drive the car for at least a week and the light should turn off. I filled the gas tank again to try and get the light to reset on its own. At least I know it is only on because of a small evaporative leak.

 

I know the light is annoying as hell.....had that happen on my '99 Civic after I changed the plugs....one of the plug wires came off the distributor, and the engine light came on. Thank god for the haynes manual......just popped the fuel pump relay fuse, and that reset the sucker.....

 

When I had a similar thing hapen (someone didn't tighten my gas cap tight emough) that same code came on. I made sure my cap was put on with the three recommended snaps.

My understanding is; if you do not care to go to Autozone or a dealer to reset, the truck resets after 50 key turns or starts in other words - (key turned completely off then completely on). I was a little impatient and turned my key off and on 3 or 4 times each time I started and turned off my truck. The light went out after a couple days.

I've also heard not to turn the key off and on more than about 10 times in a row due to fuel pump over heating or something to that effect.

 

check all the hoses at the leak detection pump, after the gas cap fix, this is the most common problen for a evap leak. see the attached pic. hope this helps.......
Create Parts List


EKO=3.7 litre
EVO=4.7 litre
EMO=5.9 litre

025-Emission Systems
420-Leak Detection pump

Item Qty Rqd Part Number Qty Line Body Engine Trans Description
1 52102 793AA 1 EK0, EM0, EV0 HOSE, Leak Detection Pump to Canister
2 52102 792AA 1 EK0, EM0, EV0 BRACKET, Leak Detection Pump
3 48914 16AD 1 EK0, EM0, EV0 PUMP, Leak Detection
4 60360 39AA 3 EK0, EM0, EV0 SCREW, .190-16x.542
5 52102 772AA 1 EK0, EM0, EV0 HOSE, Filter to Leak Detection Pump
6 SCREW, M6x1.00x11.00, [M6X1.00X11.00] , (NOT SERVICED)
7 53013 376AB 1 EK0, EM0, EV0 FILTER, Leak Detection Pump
8 53032 052AB 1 EK0, EM0, EV0 HOSE, Vapor Canister Pass Thru
9 52029 091AA 2 EK0, EV0 CLAMP
10 3820 667 1 EK0, EM0, EV0 CAP, Vapor Canister
11 6100 048 4 EK0, EM0, EV0 NUT, Hex, M6x1.00
12 53032 172AB 1 EK0, EM0, EV0 BRACKET, Vapor Canister
13 SCREW, [M8X1.25X25.00] , (NOT SERVICED)
14 53031 584AC 1 EK0, EM0, EV0 CANISTER, Fuel Vapor
15 5303 0837 1 EK0, EM0, EV0 CANISTER, Vapor
16 52102 872AA 1 1 EK0, EM0, EV0 COVER, Vapor Canister
17 SCREW, [M6X1.00X11.00] , (NOT SERVICED)


































[IMG]local://upfiles/2784/4A1938172700496BA117AE37C72BCEE2.gif[/IMG]

 

what about unhooking the negative battery cable, then turning key over a few times to clear things, and then reconnecting it? i did this and it DID turn the check engine light off ( after putting on a new cap), but about 20-25 miles later, it came back on. does it NEED to be turned off by autozone or somewhere with a computer ,or do i need to check further to see if maybe it is hose or something? but if it was a hose, wouldn't it stay on after i replaced the gas cap?