Checked. It has the proper pre-tensioned clip that came originally with the car, not like a jubilee clip. No air leaks detected and checked routing of all air hoses. Stumped as to what the cause of the periodic high idling after 15 minutes of driving. All pscan readout (incl water temp) all within spec except when this issue hits and no. of steps rise to 60-70 steps (RPM ca. 1500) from the 21 steps (875 RPM).