P0440

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Showing the Evaporative Emission Control System Malfunction code for the first time since i have owned vehicle as far as i can remember any way.
Mileage is 356k 1997 oldsmobile 88 3.8 liter.

this may be unrelated,,,last thursday i fueled up and a couple miles after that the car started sputtering, no code set at that time, the car acted as if no fuel was being delivered. ran like that for about 3 miles or so off and on, then fine. ( I figured a little stale gas or perhaps some water buildup)

ran car friday and saturday( all good), it sat on sunday, then today, on my morning drive(35 miles) it, the check engine light comes on. I get to work, pull the codes and it is the P0440.

Where to begin to check this?
 
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thanks db, we posted at the same time:::

it is the original gas cap, so i may get another one, reset code and take it from there..
 
Did you top off and flood the evap plumbing? Hot weather will compound this.

If this was a Fard it would have broken 10 years sooner
smile.gif
 
filled it till the lever clicked then got an extra 2 bucks or so to the next nearest dollar,,, I did not over fill it like i do sometimes all the way to the top of the neck!!!
 
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Originally Posted By: oilmutt
365k on the clock,please dont tell me there is no rust!

I don't know where OP live, but California cars don't have problem with rust anywhere. My previous 1994 LS400 with more than 380k miles had no rust at all when I sold it few months ago. Paint and clear coat under the sun for 20+ years are different story.
 
Clicked off and then added 2 extra dollars, sounds like the evaporator system may have been flooded like ARCO.. aluded to. Fuel doesn't need to be at the top of the fill tube to cause problems. Ed
 
Originally Posted By: Eddie
Clicked off and then added 2 extra dollars, sounds like the evaporator system may have been flooded like ARCO.. aluded to. Fuel doesn't need to be at the top of the fill tube to cause problems. Ed



so should i just clear code and wait and see....if it shows up again?
 
Systems can differ but.....a gas jockey who knew I was going on a long trip filled my neck to the back of the cap.

I got a code, do not remember the # but did feel comfortable in my conclusion that it was Boontahr's helpfulness which gave it to me.

The long trip drains the tank so I did not refill it above 1/2 way. It took 2 weeks of normal (local) driving before the code ceased returning.

I was clearing the code continually during the 2 week period.

Sure wish I could remember the code I got.
 
If the code returns I suggest looking at the video linked above. In their example the filler neck became merely abraded with time and could no longer seal.

I've seen it suggested that silicone grease be applied to the gas cap gasket to effect an airtight seal.

The real challenge here is finding the purge and vent valves should you need to test them.

Best of....
 
So far no code returns, but it is early on.

If it should return, i thought about applying a little High Mileage oil around the gas cap seal to revitalize it, before buying a new one..I can also try the silicone grease suggested by Kira.

I'll have a look at the filler neck, but i know for sure the area where the gas cap seals is "immaculate", i know it is hard to believe, but i have always cared well for this vehicle. If i had noticed any abnormality there I would have addressed it. Wish I could say the same for my wife's car, the filler neck around the gas entry and seal area on her car always seems to develop a little rust.

thanks all.
 
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I would advise to apply No Silicone grease anywhere on an engine with Lambda controlled fueling. Not Intake, not fuel, not gaskets nor oil.
I wont even wax a car due to lambda issues.
 
roger that:

should code return, then first step is to try new gas cap.. unless something else obvious shows up by then...or perhaps another code.
 
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