Wife’s car just threw a code today for an evap emissions system leak. Fuel cap seemed tight, but I snugged it up again anyway. It’s been maybe ten years since I dealt with this on a previous car, but ISTR this code will clear on its own after X key starts. Anyone know the value of X?
Or am I remembering wrong, and it’s X key starts with a persistent problem before the MIL comes on (and I’ll have to borrow a reader to reset it)?
I’ve heard it’s three key starts with some kind of genuine mileage on each.
Big help, I know!
Three starts to trigger the MIL, or three starts to clear it (or both)?
As usual for car questions you should tell us what year, make, model, engine.
The EVAP code should clear in 3 driving cycles on most cars. A driving cycle is NOT 3 key starts. A driving cycle allows time for the computer to read the input from the sensors and run a diagnostic again.
Here is an example of the drive cycle on a GM car. Just drive it like you normally do and it should allow time for the PCM to run a new test and reset the light.
What Dallas said.
Sorry, you’re right. 2011 Honda CR-V, only 30,000 miles. I know OBD2 is mandatory for any car sold in the last couple of decades, so I figured the behavior (i.e. the # of [del]keystarts[/del] driving cycles required to set/clear an evap system fault) would be the same across all models. Is that not the case?
Probably, I don’t know, I only know GM.
Because an EVAP code is usually triggered by an air leak, like a loose gas cap, what your computer is looking for is I believe in step 4 of my GM example, air intrusive.
Unless you are making real short trips your day-to-day driving should cover these drive cycles in a day or so. I wouldn’t worry about it unless it doesn’t go out after a week.
Note that with an OBD-to-Bluetooth device (~ $15) and the Torque smartphone app ( ~ $5) you can read & clear trouble codes at will.
(That’s a very small part of what you can do, but definitely useful.)