You know where your air filter is, right? Attached to the black box that is in is a mainly cylindrical black and silver item which has a wire to it and a fat hose running from it to your intake manifold on the engine. That black and silver device is the AMM.

The classic test for it is to unplug the wire from it (with car OFF ONLY) then start the car and see if it runs better. If so, then your AMM is bad. The car will actually run fairly well in "limp home" mode with the AMM unplugged, but in the long run it's bad for the car and you will get poor gas milage.

It seems most AMM failures are caused by the thermostat in the airbox going bad and allowing hot air in through the AMM all the time instead of only at startup. I think it's an excellent idea to eliminate that big silver hose that goes from the airbox around to the exhaust manifold to completely eliminate this problem. You may have to put it back for inspection if your state has visual emissions checks. Or you can replace the bad thermostat.

I have had very good luck withe used AMMs from my local pick-n-pull and they can be had from eBay a lot more cheaply than new ones (I have sold quite a few on eBay myself). People have reported bad luck with rebuilt ones.
--
Andy in St. Paul. '89 244 153K mi, '91 745 Regina 202K, '88 244 184K