Q: Bad fuel mileage, no black smoke, no check engine light.

asked by on

My car has an issue where I'm getting under 20 mpg, I have inspected the fpr, Maf, and the fuel injectors. Car also has sluggish acceleration, and the engine shudders under WOT below 3000 rpm. My car has 273,000 miles

My car has 273000 miles.
My car has a manual transmission.

Hi there. Most of the time, poor fuel mileage is due to dirty O2 sensors, EGR valve, mass air flow sensor or throttle body itself. If these components are dirty or damaged, it can also cause engine misfiring or rattling during acceleration as you’ve described. To identify the source issue, it might be a good idea to have a professional mechanic come to your location and complete a car is getting worse gas mileage inspection.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Bad fuel mileage, no black smoke, no check engine light.

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: Cranks but won't start - 1999 Mazda 626

Hello. You should have the vehicle checked for loss of fuel pressure. If you have no fuel pressure, then inspect the fuel pump connection and check for power to the pump. If you have power to the fuel pump, then...

Q: The engine on my car has seized and is a write off. Should the manufacturer accept any liability?

Unfortunately, your car is outside the warranty period, so legally speaking, they do not have to warranty your motor. It is unfortunate your car has suffered so many failures and very frustrating for you because you have done what you...

Q: I got a 2002 Hyundai elantra and it jerks when i stop are i stop and feet is on the brakes like it wants to cut off engine light

Hi Jessica. Thanks for contacting us today. There could be a few reasons why this is happening. Most of the time, stalling issues like you've described are caused by fuel system components that are excessively dirty or malfunctioning. This could...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...