1998 Ford Taurus Emission

The AIR code- Look for broken vacuum lines to the AIR diverter valves, broken/missing belt on AIR pump, damage to the hoses from diverter valve to the "gulp" valves at the exhaust manifolds. If all good, start and warm up car, check for vacuum at control valve on diverter. If ok then might be the gulp valves, they are one way and sometimes get rusty and stuck in position. The EVAP code might require a trip to teh shop for a smoke test to find the leak, the system will detect very small leaks

There should be a tube or hose with a valve in it running to each exhaust manifold. You will see a vacuum line going to it. One on both manifolds. The valves can be tested with a vacuum gauge/source. You can apply vacuum (16 PSI or more) and you should hear the valve open and then slowly close. If you remove the hose or tube, you can see it opening and closing. If it's working properly.