Check engine light on but the car run smoothly
I have a Ford Escape 2001 with the V6, 3.0L. A few years ago I had the engine replace with a rebuilt 2004. Little bit after the engine light went on with a P1406 code but the car was running fine, replaced the EGR valve reset the computer, after driving for about an hour the light came on again with the same code, but the car is still running fine, check and clean the sensor, reset the computer and same problem… or lack of problem!! Light comes on after an hour or so, the car still run smoothly in the city and on the highway. The only exception, once in a while when Idling the rpm will go up (from around 700rpm to 1100rpm) for less than a second.
My problem is, I moved to Toronto and an Ontario emissions test station will not even start the test on a vehicle with a check engine light on or if the check engine light is inoperative.
Thanks in advance for your help!