I'm a new kid on this forum and am glad to see you Cat owners out there keeping this car popular. Now, on to my dilemma.........
I have a '99 Cat which emits an undetectable noise. I thought it might be the AC / heater unit, but with that turned off, the noise continues. The event usually occurs when I'm "cruising"
on the highway. When I hit 85 mph, that's when the noise occurs. It sounds like it's coming from that duct between the defrost buttons and the mode button on the AC/heater console.
Don't know what is happening, but open to all suggestions. Thanks in advance.