Suzuki Repair: Running too rich, poor mileage, haynes manual


Question
I have a 1992 Geo Tracker with a 1.6L TFI engine. It is getting poor mileage (20MPG) and sometimes after you let off the gas pedal and then apply the brakes there is an exhaust smell inside the car. The tail pipe is very black. I suspect an emmision control problem, but where should I start to diagnose this problem.  

Answer
You can check the oxygen sensor to see if it is generating a voltage signal(should vary 0.2v-0.9v).  The tail pipe will be black, because that is a normal color for any gasoline vehicle with a catalytic converter.  There are any number of other things that could cause low fuel mileage, and the only way to diagnose this is with a good(Suzuki/Geo, NOT chilton or haynes)manual.  If you are having trouble with the diagnosis, you can try IATN.ORG.  They have a shop finder and with this resource, you can  find a technician who can diagnose your vehicle, and give you an accurate estimate.