Recently our 2007 Fit Sport stopped maintaining speed up grades. The proper light comes on indicating that the speed is set, but it just drifts down from 65 MPH to about 40 MPH before I finally just put my foot on the gas.

Going down the same grade it used to maintain 60 MPH without going into Sport mode and putting it in 3rd. No longer does that, either.

My mechanic thinks that this is a clogged catalytic converter issue, as opposed to electronic. He thinks that there is a pending cat converter code that is causing the cruise control to not set speed.

Question: If that is the case, that there is a pending cat converter code, would the system even let the light come on that indicates that speed has been set? Or would pressing that button not do anything?