Check engine light came on in '02 Seqouia. I tightened gas cap, took it off and waited several days and more miles, but light remained on. Took to shop and they said charcoal canister needed replacing. 400$ later, check engine light is still on. Took back to shop still got an evap signal on scan. Technician says he found a and loose hose so problem fixed. My question was did I really need the charcoal canister changed? His answer was that it was a different code in evap system... doesn't sound right to me... comments?

What code was originally thrown?

What code appeared later?

Most of these situations can be avoided by not pumping in more gas, when the nozzle cuts off.

Sounds right to me. When my 'check engine' light comes on it is usually an environmental issue and my garage uses the computer, attached to an outlet under the dash of my Subaru outback legacy to pinpoint the problem. Last time it was 'evaporation in the gas tank', the time before that it was a loose gas cap. So yes, there are different codes on that little computer they use. Environmental issues with cars are a big deal up here in Ontario. About every second year I have to have an emission check done on my car.

Tick

What code was originally thrown?

What code appeared later?

Most of these situations can be avoided by not pumping in more gas, when the nozzle cuts off.

So true! Bear with me...

I have too many times watched or listened as people at other pumps continue to squeeze and squeeze that handle, click after click, thinking they're doing themselves a favor by "getting as much gas this stop so I won't have to stop as often", when overfilling like that can and will result in forcing raw fuel into the charcoal canister (A canister that is designed to accommodate fuel vapors, not raw fuel.. ).
Since the canister cannot deal with this violent overload, it ceases to operate as designed. The next step is to store a fault code (DTC) in the vehicle's PCM and conveniently turn on that pesky light that tells you something's wrong.
Often, you will hear things about "EVAP" systems. EVAP should be synonomous with "vapor" (there's that word again).

Please, re-read that, starting with "I have too many... " and ask yourself if that's you doing this to yourself.

Intsead, if you have the chance, fuel early in the day (you do actually "gain" from this due to expansion).
Don't wait until the low fuel light comes on (if equipped), but "cycle" your tank by driving until it shows about a quarter tank and then fueling to the first click only and stopping there.
I'd even suggest using fuel from different stations periodically, but always from stations that are "high volume" stations as their tanks get that routine "cycling" I mentioned before. :cool:

Absolutely spot on sir Rich. You too Tx. (saved me a bunch of typin')

Thanks for the replies. I was only told that there was an evap code and didn't know to ask which one. I do not top off the gas (I am too impatient) but I haven't been the only driver of this car and have a teenage son who probably does this. The SUV has almost 150,000 miles and had been smelling of gas in the garage and after my son filled it. This makes me fell better and that the expensive work was needed. I guess it was just coincidental that a hose came loose right after this was fixed. The Seqouia was bought new in 2001 and this is the first thing that I have had to fix. I will make sure that my son knows not to top off the gas and have him fuel it for me in the mornings.
Thanks again :)

Sounds valid. But when this light comes on and its supposedly the canister, what do I do after? Like do I let the gas gauge drop to almost low and refill it but of course not making the same mistake of going beyond the one click.