1997 Mercury Mystique Raw Gas Smell & bad mileage

KSPINNER

MEMBER
1997 MERCURY MYSTIQUE
6 CYL
FWD
AUTOMATIC
210,000 MILES

We get a strong raw gas smell only during the warm weather when we are driving. You can not smell it when the car is stopped, parked or when it is cold out. Also it doesn't smell all the time. We cannot see any gas leaks. We are also getting very bad gas mileage. What could be the problem and what would be the cost to fix it?

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

1997 Mercury Mystique Raw Gas Smell & bad mileage

Running rich:

Possible causes include a bad O2 sensor, excessive fuel pressure (bad fuel pressure regulator or plugged return line), leaky fuel injectors, dirty air filter or restricted air inlet, or a defective coolant sensor that prevents the engine management system from going into closed loop mode.