Skip the auto shop - Our mechanics make house calls

Q: Low performance

asked by on

I own a 1992 Grand Marquis. Time after time my engine performance is getting lower and the car fuel consumption gets up. I can't keep up with speed even if I put my foot on pedal badly. I changed fuel, TPS, air cleaner, and spark plugs, and cleaned the MAF with a cleaner but my performance remains the same :(

A: Hi there, thanks for writing in. I’d be hap...

Hi there, thanks for writing in. I’d be happy to offer my insight. I would recommend checking the EGR valve and EVP sensor. The EVP sensor will tell the solenoid to open and send vacuum to the EGR valve. Right after it does this, it looks for a voltage change from the EVP sensor. If it does not receive the proper signal, it should trigger a fault code. You should have a check engine light on in your dash.

If you would like help with this inspection, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make any repairs as needed. The technician will also have a scanning tool to download codes that will help pinpoint the issue.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Poor gas mileage

Turbochargers are for producing more power from a smaller size engine. Fuel economy is not maintained when a turbocharger is used. Turbos only operate under a power request of the throttle position. They introduce more air into the engine, and...

Q: How do I know if I need upper or lower control arm bushings for the front? 1999 Mercury Grand Marquis

Hi - worn, damaged or "soft" control arm bushings will usually make themselves known as "loose" steering, requires more frequent or constant "corrections" from the steering wheel, abnormal tire wear, or the inability to get the front suspension aligned properly....

Q: engine knocking from the bottom near the camshaft pulley

Hi there. An engine knock from the bottom of the motor could suggest several problems. When the crankshaft connecting rod bearings, main bearings, and a variety of other rotating assembly components fail, this can cause a sound such as this....

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...