Toyota Repair: toyota fourunner, airflow meter, blowing gas

Question
'95 Toyota fourunner w/ 3.0 v-6, 150k mi., smells like it's blowing gas out the tailpipe. It gets really bad mileage and has a rough idle that smooths out at highway speed. Check eng. light is on, idles around 1000 rpm in park and 600 in gear. Selling the truck this week and would like to get full value for it. PLEASE HELP!!

Answer
I can help a little more by having a diagnostic code, you can have it scanned for codes at most autoparts stores like autozone, at this time my best guess is that you are going to get an O2 sensor malfuction code due to the rich air fuel condition. This could be caused by a leaking cold start injector or fuel injector or even a bad engine control computer or airflow meter.