Gas-X for my car?

My 2003 Toyota Avalon keeps throwing up this Check Engine code which indicates a gasoline vapor leak. I don’t recall the exact number. My mechanic performed a pressure test with smoke, nothing found. I also replaced the gas cap. Still, after the code is cleared, it appears again in a few weeks. Any ideas or suggestions?

Was the new gas cap from Toyota? Some aftermarket caps don’t work so well.

I got the replacement cap from O’Reilly.

Try a gas cap from a Toyota dealership.

Yeah, I’ll do that. If the fix fails, I’ll repost here. If it works, I’ll probably forget to do it.
It will be weeks before I know.

Toyota EVAP vacuum switching valve diagnosis and repair

Excellent videos on this site.

I highly recommend one of those $35 code readers. It’ll save you so much aggravation. You can use it to clear the code, then you’ll know much sooner if there’s a problem.

With the evap codes, there are several problems that the smoke test does not detect. See this video for more information.

OK, so the problem returned with a Toyota gas cap.
The code is P0442.

Check for holes or cuts in the evap lines.

Was the car ever in a wreck on the fill side. If so the fill hose could be damaged. My daughter did this with a pole at a pump.

OK. It was the ECS cannister. The valve on it was bad, but you have to buy the whole cannister to get the valve.

Stop voting for liberals and perhaps we’ll have fewer BS problems that we address with our cars that don’t impact how well they run.

Stop voting for liberals and perhaps we'll have fewer BS problems that we address with our cars that don't impact how well they run.

Cars today pollute far far less…have better gas mileage…AND have magnitude FEWER problems then vehicles did 30 years ago. It’s obvious we’re heading in the right direction.

Which decade had the worst-running cars due to emission controls? If memory serves, it was the 1980s, when we had a liberal named Ronald Reagan in the White House overseeing the EPA. Let’s not forget it was a liberal named Richard Nixon who gave us the EPA to begin with. [/sarcasm]

@MikeInNH…I will partly agree with you. It’s true that vehicles pollute less, have better gas mileage and are safer. Your contention that newer vehicles have “magnitude FEWER” problems is simply wrong. My grandfather, father and I drove vehicles that rarely had problems as long as they were serviced.

Newer vehicles come with “built in” problems like the CEL system, 02 sensors, catalytic converters, alarm systems that won’t let you start your own car, TPMS and anti-lock brakes with faulty sensors. Electric door locks and power windows are convenient but they break down far more often than manual door locks and windows. I could go on but I think my point has already been made.

Missileman…I agree with you 100%. Your point was made before you even listed examples.

I’ve had cars dating back to 1952 Chevies. There is NO QUESTION that modern cars are loads more reliable. Admittedly you can’t replace a fuel pump along the side of the road in Nebraska in 15 minutes as I did, but you can go 150k without a fuel pump change–unheard of in those days. My Dodge Dart–a legendary reliable car–had 5 starters in 215k miles. And at least 10 ballast resistors. 2 or 3 water pumps…

My Toyota Avalon–which had the problem discussed before this thread was hijacked–has had 2 problems in 110k miles that are non-maintainence. A loose window glass and this cannister. Compare that with any car in the “good old days”.

This change is the result of new technology. It probably would have happened with or without pollution controls.

All the pollution control stuff took about 20 years to “get right”-- for GM and Ford.

But now, modern cars are far more powerful, reliable, fun to drive, and economical on gas than the stuff I grew up on.


Yeah, me too. I’ll take my modern car with it’s reliable technology any day.

My grandfather, father and I drove vehicles that rarely had problems as long as they were serviced.

I too have owned cars since the 60’s…Modern cars are far far more reliable then cars 30+ years ago.

Glad to hear you found your problem. Just so you know for the future-

These year Toyotas are notorious for filler neck rusting. My 03 Camry started having issues after about 5 years. Look online- there’s practically an industry around replacement necks. Remove the cap and check the seating ring around the lip of the neck. If it’s pitted even a little, you’ll get EVAP codes. I didn’t like the cost of a refurbished one so I’ve been sanding mine down every year or so and painting it to restore the seal integrity.

BTW- IIRC, the EVAP check won’t occur unless the tank has a range of fuel from 1/4 to 3/4 along with a number of other conditions. So be sure you check the actual conditions for the test so you’re not chasing your tail waiting to see if it’s fixed or not.