2003 chevy impala 3.4
using innova 3100 diagnostic tool scanner reads no fault codes
No engine light on in car. Let car sit 8 hours on three separate occasions.Ran drive cycles. system status light stays yellow. will not go into readiness which is green. All seven items pass emissions except ev - meaning evap. Has anyone encountered this problem before and if so, how did you repair?
Could sensors be bad and won't send fault codes.

 

one of the conditions for the evap monitor to run is: the fuel level must be less than 3/4 full and more than 1/4.

 

It has 1/2 tank of gas

 

1/2 tank of gas. New battery. Ran Drive Cycles 4 times. 250 total miles driven over a week.

 

I had a similar problem with my Saturn years ago. The thermostat was bad and never allowed the engine to come up to full temp, so the evap test was inhibited until temp "X" was reached.

 

Thanks Frank3. Got halfway through drive cycle step 2 and ev light came on within four miles. Unhooked the fan motor and didn't turn AC on and it passed emissions. Thanks for your feedback, that suggestion did the trick.

Tony

 

Tony, I'm glad things worked out for you!