Prerequisites: no codes present (even a pending code), engine coolant temperature is above 75 degrees f; barometric pressure above 72kPa.
1. Idle vehicle five minutes or until it is in closed loop.
2. Accelerate and drive for one minute at steady speed above fifty mph.
3. Coast vehicle down to twenty mph (vehicle in drive, do not use the brakes).
4. Repeat steps two and three four times.
The EVAP can be a real bear to set because it takes a very narrow set of conditions to make it set.
For instance if the fuel tank is under 1/4 or over 3/4 of a tank it won't run the test.
If the engine and air temperatures do not match it won't run the test.
I have seen the EVAP take a month to set.
You also may want to visit a dealer and have them scan it with a dealer level tool. There are a couple items that set codes that do not turn on the CEL but will block the monitor tests from running.
Friday, January 27th, 2017 AT 7:14 PM