autozen,
thank you. I will try this out asap.

btw, is it possible for a old catalytic converter to essentially block the exhaust and thus cause it to behave this way too? i.e. when it gets hot, it blocks the exhaust and when it is cold it lets the exhaust thru.

does this have anything to do with the idle control valve? <--- saw another post that talked about this.

thanks again for your help!