Q: Car revs up but does not drive faster than 40 mph on a flat road.

asked by on January 28, 2017

I replaced the catalytic converter at about 150000 miles. Drove about 300 miles check engine light came on. Went to AutoZone scan said probably a bad upstream oxygen sensor. Replaced both sensors and light went out. Got gas one day and check engine light came on again. AutoZone said it was probably the gas cap. Replaced cap and reset light. The other day I pulled out and car died. Got it started back but it won't do over 40 on a flat road. Engine will rev but the car slows down. Any idea what might be wrong? The check engine light is not on so I am puzzled. Thank you.

My car has 163000 miles.
My car has an automatic transmission.

Hi there. For the engine revving up and the vehicle slowing down, the transmission could be slipping. Check the transmission fluid and see if its full and red in color. If the fluid is full, then the transmission could be slipping while in gear. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your transmission.

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

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

What are the best 50/50 antifreeze options to use for my car? 2002 Honda Accord

Hi there - there are pretty-much just 2 issues when selecting engine coolant. First question is "What "type" coolant should I buy?". Glycol-based coolant tends to be the green stuff. Low-phosphate, for all aluminum engines is pink or orange. (Best...

What is the cost to replace an 02 sensor in a 2003 Hyundai Elantra

Hello, thank you for writing in. If you are going to have someone replace the oxygen sensor, you must take into consideration the price of the part and the cost of labor. For a technician from YourMechanic to replace the...

Transmission won't go in reverse.

Hi there. Sounds like the transmission shift position sensor is not working properly. I recommend replacing the sensor. The transmission position sensor is designed to tell the computer (ECM) what gear the vehicle is in. If the dash is saying...

Related articles

The Best Used Cars to Buy If You're a Doctor Who Makes House Calls
If If you are a doctor who makes house calls, reliability is likely to be at the forefront of your mind when it comes to choosing a used car. You also expect a certain level of comfort. We have...
How to Decide Between Manual and Automatic Transmissions
There There are a lot of decisions that have to be made when buying a new car. Everything from choosing a make, model, and trim level to deciding if upgrading the stereo is worth the extra money. One of the...
A Buyer’s Guide to the 2012 Hyundai Sonata Hybrid
When When Toyota first introduced the Prius, the idea seemed to be that all hybrids and electric cars had to have their own specific models and that they couldn’t look like normal cars. A lot of consumers weren’t too thrilled...