Service engine soon appeared on my dash yesterday. I went to autozone and they told me it was an evap leak. I checked the gas cap and it was loose enough to remove without unscrewing. So I clamped it down until it clicked. I’m hoping this was the reason for the service light. How long should I drive the vehicle before expecting the light to shut off again? Aka when should I start looking for other problematic sources.

 

Buy your on ob2 tool you are going to need it anyway, you can delete codes and turn off your check engine light
https://www.google.com/search?source...76.tQs0BkQbxUY

 

Also when you get free codes read = write them down. P0441 is common and caused by a loose gas cap or a faulty sticking Purge Control Valve.

 

So will it turn off on it’s own if the gas cap was the problem?

 

That bulb takes years to burn out

If it was just the cap a few complete drive cycles will sometimes clear the fault. Or stop back by Autozone, see what the code is and then clear it.

 

I get that one every now and then.
I clear the code with my cheap as dirt wifi obd and DashCmd. I recommend. Way cheaper than a real OBD tool.

 

Yes, if the problem was corrected. But, it will take a couple of drives cycles to clear it. If you have a scanner you can clear it and if it comes back then nit fixed.

 

you turn off service engine soon yourself.
You just ground two terminals in a little relay unit which is in passenger's right kick panel.

 

I had a brand new 4Runner that I had the exact same thing. It took a few drives to go off. Late the next day I think. But like others have said you can use a diagtool to clear it. One of the best purchases I made for this vehicle to date.

 

It didn’t shut off after 1 week of having the gas cap tightened. I picked up a garden variety fuel cap and replaced the purge valve. I shut the light off with a plug in code reader today. Let’s see if it stays off.

P0455 code