Motor Vehicle Maintenance & Repair Stack Exchange
Motor Vehicle Maintenance & Repair Stack Exchange

Questions tagged [fuel-cap]

Tightening cap that seals the fuel system form the filler neck to the fuel tank.

Tightening cap that seals the fuel system form the filler neck to the fuel tank.

23 questions
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Why would a new gas cap cause the "check engine" light to shut off?

This happened to a friend of mine: The "check engine" light came on in his truck (Toyota). He replaced the gas cap and the light shut off. Then I also had a "check engine" light come on in my 1994 Chevy. I took it to the dealer, they hooked up to…
No Clutch
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4 answers

How important is a fuel cap?

I lost my fuel cap a couple months ago and haven't bothered finding a replacement. I haven't noticed any issues with it, but I'm wondering whether it's causing any damage or reducing gas mileage or anything.
David Ly
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2 answers

Does waiting until the gas cap become faulty cause any damage?

The description for a fuel tank cap says: You can prevent unnecessary service costs by replacing the gas cap on modern vehicles before they go bad and the check engine light appears. Is this advertising baloney? Is there actually something that…
Calaf
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Can't fill car up with gas

I can no longer fill up my gas tank in one go. This started gradually over a few months, initially only happening at one pump at the closest station. Now, however, I can't get more than a gallon or so before the pump clicks off. I then have to pull…
3Dave
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VW Golf fuel filler cap will not unlock

The fuel filler flap on my 09 VW Golf estate (diesel) will not unlock. I have tried locking and unlocking the car which should relase the filler flap but it remains locked. The owner's manual says there is no method of manual relase on this model.…
Lynne
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Could a bad purge valve be my problem?

I had my "check gas cap" notice show up on my 2008 lacrosse dash. I checked the cap and cleaned it off, The notice appeared the next day so I removed the cap and covered the opening with a plastic bag securing it tightly around the opening with…
JACK
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What should I be looking for in a gas cap?

I've misplaced my fuel cap because reasons. I need to get a new one, but I'm not sure what exactly I should be looking for or how to figure out what will work for my vehicle. Are all caps the same? Are gas caps universal enough that buying one…
David Starkey
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P0442: Faulty EVAP System

After seeing my CEL come on in my '05 Mazda 3 (just passed 100K mi.), I used my code reader to find out that the code was P0442. So I naturally came to this website to see what I could find on the subject matter. The only question on this site (at…
tarheel
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Cleaning the gas cap to rule out that tightness is the cause of the "check engine" light

The gas cap on my 2003 Pontiac Vibe used to make a slight sound of "pssstt..", the sound of some air either entering or exiting from the tank as I was opening the cap. Two months ago, the gas cap stopped making that sound when I unscrew it to fuel,…
Calaf
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Excessive vacuum making new fuel cap hard to remove

I recently had the gas cap changed (told there was a vacuum issue) at inspection. It is very difficult to remove this new cap when I go to fill up. Now the car is experiencing episodes where it does not want to start (wants to turn over but it…
Dee
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What can cause "check gas cap" warnings other than a loose gas cap?

I have a 2006 Saturn Ion, and a few months ago I started getting a warning about my gas cap. Specifically, as I was driving the dash display would beep and say "Check Gas Cap." I bought a new cap to rule out that issue, and I've been diligent about…
Luke
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Check emission system displayed on dashboard display

For the last week it has been extremely cold where I live (varies between -27 to -33 degrees Celcius). Is it possible for a fuel cap check valve to freeze open? Last night leaving work the display on my 2012 Honda Civic told me tighten fuel cap and…
Old_Fossil
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Does a full fuel tank speed up the CEL turning off after changing the fuel cap?

Consider this scenario: The CEL (check-engine light) is on. The fuel cap is subsequently replaced. The fuel tank is half full. I am wondering: Is it advantageous to fill the tank to the top to speed up the time it will take the CEL to go off? (we…
Calaf
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OBDII Scanner showing code after the light is gone

My check engine light turned on. I used my OBDII scanner and got back the codes P0441 and P0455, which is sometimes caused by a loose gas cap. I checked my gas cap and it was indeed loose. I tightened it and the light went off. However, when I use…
Bretton Haug
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GMC Envoy stalls when air conditioner is on and idling

2004 Envoy only dies when A/C is on and idling if it is in park or neutral no problem. Also will not crank after fueling once started will continue to turn over till refueling again. And service engine soon light is on stating needs new gas cap.…
Diana Hunnicutt
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