Q: Q: Bad gas mileage

asked by on

Notice bad gas mileage then service engine light came on. Took it to shop where they replace one catalytic converter. Light went off gas mileage still bad. After driving about 1000 miles service engine light comes back on. Only getting about 12 miles to gallon. Car rides fantastic performs well only problem is the gas mileage.

My car has 99000 miles.
My car has an automatic transmission.

Hi there. Quite often a damaged catalytic converter will mask other mechanical issues that impact fuel economy. One culprit in particular is the EGR valve. The EGR valve works in conjunction with the catalytic converter to help reduce particulate matter emissions coming from the vehicle. Overtime it will become clogged with excessive carbon build-up and can reduce the fuel efficiency of a vehicle by as much as 40% if it’s damaged or dirty.

However, there are other parts on your Infinity that might also be causing your poor fuel economy, which is why I’d recommend having a professional mechanic, such as one from YourMechanic, complete an inspection of your decreased gas mileage. This initial service will allow them to properly inspect the vehicle and determine what’s causing the problem, ensuring the right repairs are made.

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. Q: Bad gas mileage

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: The emergency brake is not working and multiple brake lights are on

The OBD-II error code P-0501 is a generic code that indicates an issue with the transmission speed sensor. This component is vital in the operation of the ABS and traction control system, which is probably why the light is illuminated....

Q: What can I do to help my 2009 Audi S5 get better gas mileage?

Often times, owners have unrealistic expectations for their vehicles when it comes to fuel mileage. This is because the EPA estimated fuel mileage rating give to a vehicle doesn't stand up to real-world driving conditions. That being said, there are...

Q: Can I put E85 in my gas tank?

If the previous owner specifically asked you not to, they may have known about an issues the vehicle has when using E85. It may be necessary to visit your local dealer to take a look at the truck to see...

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 Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.