1999 Mercury Sable Car looses power up hill

RATISFATTER

MEMBER
1999 MERCURY SABLE

Engine Performance problem
1999 Mercury Sable 100000 miles

For the 3 years since I've had my car, it looses power going up a hill almost to the point of sputtering and dying (though it hasn't died on me). It also tends to frequently loose power over about 50 mph. It's like the gas pedal doesn't want to press hard enough. The more I press it the more it sputters. Driving on flat road or low speed it works fine. Mechanics have told me a million different things: alternator, vaccum leak, spark plugs, even just to shift gears (this did not work). What could it be?

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Oxygen sensor
Catalytic converter
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires