if i have a clogged cat...will that cause my engine to idle higher??

 

i have only had one experience with a clogged cat, it made the car run as thou i were pulling a house trailer, do not recall if the rpms were high thou,,,but at least you will have to replace the cat and then you will know..

 

NO, more likely a low idle if anything. You are severely restricting the exhaust.
hanman

 

I don't think the RPM's were effected by the clogged cat, but the car was seriously sluggish revving, and refused to make much power higher up in the RPM range. High idle is usually a sign of a vac leak somewhere. When my bac/acv went funky I had a high-hunting idle. I just popped the vac hose off the bac side and plumbed it directly into manifold vac (I'm guessing that the bac solenoid sh*t the bed) and she not only idles dead solid now, but the acv works now (I had the feeder line plugged before) so the a/c doesn't try and stall the car.

--matt