my car will die when you let off the gas. Why? on 1999 Buick LeSabre

I have changed spark plugs and wires, replace fuel filter

Asked by for the 1999 Buick LeSabre
Could be a vacuum leak, or a bad mass air flow sensor or several other things, if you have a yellow service engine soon light on, then it means that there is a code that will help determine what is wrong with your Buick. Get that code, you will need a scanner to read it.

here are some shops: