Check Engine light and getting Gas

Will try this one last time. Get Gas, Check Engine light comes back on, Reset Check Engine light by way of battery, then it goes away for awhile. Weeks sometimes or more. When it usually comes back in it is always after gassing up. No Codes to download as usual. Reset batt and gone for a few more weeks. one more time. Gas cap? Charcoal Canister? Any final answers form the experts on here? Gas cap looks brand new and tightens like it should and no wear that I can see. THX

DO cap then go to point B if needed or? THX in advance. Love this page.

 

If the mil light turns on, the ecm is seeing a fault. Hard store or soft store, a scanner will be about to see

 

There's hundreds of codes that can turn on the CEL, whithout knowing what code(s) you have we can't help you.

 

I connect my code reader and it connects then says there are no codes to read? Am I missing something? I know my code reader works as I tried it in another car and it read the codes.. other than the light nothing seems wrong.

 

What kind of scanner?

 

Check for pending codes and give us a list of monitors that have completed and ones that are incomplete.

 

Your positive you do not have another circuit grounding back through the MIL light. If you are unable to ever have a stored code.
Since it seems you are unable to turn the light off with your code reader1

 

Are you checking the code before you clear it with disconnecting the battery? Because the order you say in first post sounds like you are clearing the code then checking it? It should read a code if CEL is on

 

Swing in to a parts store when the light is on and ask them to scan

 

When you see the light come on, hook up the scanner before even shutting the truck off

 

This is my reader as I said it connects and then no codes to download. No I am not sure if I have a short causing the light to go on but I have read several other post on here by people that have had tue same. I will try the gas cap. I have tested my reader on my Pontiac Vibe that also has a check engine light and also no codes that one also seems to be on and off when I get gas. I did try my reader in a minivan and it dod give me the codes.

 

Some of those cheaper readers won't work with pre-CAN vehicles which is most vehicles manufactured prior to between 05 and 07, Tacoma's didn't have CAN until 05.

 

Ok I have a mechanic with a better one. will go to him next time it goes on. A new gas cap is 15 bucks so may try that first also

 

Here's a possibility.
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Are you "topping off" your gas tank when you fill up? Perhaps you like to top off to pump total to the next whole dollar. Like from $31.42 to $32.00 even. Or maybe you just want to fill up your tank with every conceivable drop. And so you give the nozzle two or three extra squeezes to click-off before you get backsplash?

If so, you are quite likely over-filling the vapor space in your tank and the fill tube. Your fill tube has an overflow relief and a vacuum break relief port. Fill tubes are not a simple piece of flex pipe anymore. So if one flood's it with gas on an overfill, you *will* saturate the EVAP system charcoal canister with liquids - which it is not designed to handle. The EVAP system charcoal canister is designed to handle vapors that are sucked into the engine by the EVAP system itself instead of being vented to atmosphere.

But when your charcoal canister is saturated with liquid, the EVAP system cannot pull a vacuum on your tank. And *that* will throw a CEL. Which may eventually clear itself as your charcoal canister dries out or the engine is able to pull the vapors into the intake.
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That code reader you are using is obsolete.

Get yourself an

$90 Innova 5210 OBD2 Scanner & Engine Code Reader, Battery Tester, Live Data, Oil Reset, Car Diagnostic Tool for Most Vehicles, Bluetooth Compatible with America's Top Car Repair App

Innova 5210 handheld scan tool from your local brick-n-mortar auto parts store. They are less than $100 with a coupon. This is an instance where you can also order one from Amazon and have it on your doorstep in ~2 days.

HTH and good luck

 

Interesting. Funny you should says that, I DID top off in Kelowna before this happened and it spilled down side of truck.

 

OK! Appreciate the honesty.

Stop doing that. ASAP.

It is A-OK to leave the pump filling while you run inside for gum, a Slurpee, a pack of smokes, whatever. But when you come back outside and the pump has shut-off, then the *only* thing you should do next is rack the nozzle back in the holster.

Over-filling is NO BUENO.

Consider yourself lucky if all you are experiencing is temporary CELs. Countless vehicle owners have needed to spend hundreds and hundreds and hundreds of dollars to have an EVAP charcoal canister swapped out because it was over-filled and wouldn't drain or dry out.

 

Actually I never do it but now that I know that I won't.. once is a blue moon I do it cleaning windows etc. But usually I get a half tank a week.

 

Get yourself a more better scan tool and start checking for codes. You might have a small EVAP system vacuum leak.

FTW!