Hi! I recently got a '19 Avalon XLE with 58k miles, everything was going perfect until recently, at 61k miles, I got a Check Engine light on the dash. Car drove fine, sounded fine, but I took it in for service immediately. The dealer’s service center said that it was a faulty fuel purge valve (and maybe also mentioned a fuel cap?).

The problem parts were replaced, but since then the car has been getting absolutely awful gas mileage. A full tank gets maybe 200-220 miles, and in the city we’re getting between 11-13 MPG. On the highway I’ll get maybe 22 MPG if I’m lucky, with like 15 MPG combined. Before this, we’d easily hit 31 or 32 on the highway, and average of 24. I drive super gentle and always try to maximise fuel efficiency.

Has anyone else experienced similar issues? Does this sound like the dealership did not properly replace the part? It’s weird that the problem would only arise after having the check engine light dealt with.

How much do you get on a full tank? I know the Avalon has a rather small fuel tank, but I used to get 340 miles+ when driving on the highway. ~200 is crazy low.

Appreciate any advice

  • kwumpog@alien.topBEnglish
    1·
    1 year ago

    Don’t normally actually measure, but when I fill up my 19 Avalon it tells me about 380 miles to empty. I normally keep it in eco mode and drive it like a grandpa.

    • photocactus@alien.topOPBEnglish
      1·
      1 year ago

      I didn’t normally measure too, but past few times I filled it used gas extremely quickly. When I fill up it’ll say 320 miles to empty, but then after a couple of miles it’ll re-assess and adjust the predicted miles to empty range. Currently full tank (99% full) and it says 270 remaining. It’ll keep adjusting so that at a half tank it’ll say like 110 remaining, etc.

  • Ferowin@alien.topBEnglish
    1·
    1 year ago

    It sounds almost like you have a fuel leak, but that shouldn’t be possible.

    The fuel system automatically pressurizes and tests the fuel system for leaks. If there were a leak, that’s when the check engine light comes on.

    I’d take it back to the dealer and have them re-verify the work they did before. You could also take it to a third party or auto parts store and ask them to check for set codes. Not all codes set a fault light, so you might get an idea from that.

    • photocactus@alien.topOPBEnglish
      1·
      1 year ago

      It certainly feels like a leak, but I think it’s just burning fuel rapidly.

      Thanks for the advice. Gonna see what the dealer says, and if they can’t help properly I’ll take it elsewhere for a diagnosis.

      • Ferowin@alien.topBEnglish
        1·
        1 year ago

        The only way it would burn that much fuel is if it were injecting it into the cylinders. That would cause a massive problem with your exhaust system and cause a check engine light because it would be running very rich.

        Are there any other problems?

        • photocactus@alien.topOPBEnglish
          1·
          1 year ago

          Thanks! No other problems, and no smoke issues from exhaust. Will take to dealer today to try to get them to diagnose. I’ll update the post if I find out

  • Sudden-Mobile-3123@alien.topBEnglish
    1·
    1 year ago

    On my Elantra I accidentally pinched/ broke a wire to the intake runner motor and got like 12 mpg in city took Dealership they said code was present on there obd but no cel on car. Was throwing the parts cannon at it. It’s best to let the pros do this type of work.