Q: Reduced engine performance that smooths out after 40 MPH until acceleration.

asked by on

Vehicle runs roughly and has a read out thats says reduced engine performance. Initailly, the vehicle runs rough at 40 mph, then smooths out until I try to accelerate.

Hello, being that the engine and transmission are computer controlled, a scanner needs to be connected to retrieve codes. If there are no codes present the technician will be able look at data retrieved by the scanner and come to a possible solution. When symptoms like this occur with the "reduced engine performance" message, the vehicle is going into limp home mode trying to protect the engine and or transmission from further damage. You should enlist the aid of a mechanic to inspect your engine.

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. Reduced engine performance that smooths out after 40 MPH until acceleration.

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: Wont start after timing belt replacement

If you are getting fuel and compression, then you need to check to see if you have spark. If you do not have spark then test the ignition system or crankshaft sensor using a scan tool. If your engine was...

Q: I am having issues with my ABS/AWD and car is in safe mode

The U1000 code is the focus of a Nissan Technical Service Bulletin (TSB) and thus the applicability of that TSB should be considered first. With multiple codes and some implicating controllers and basic CAN functions (U1000), the Factory Service Manual...

Q: Grinding/popping sound when turning wheels all the way and slight shake in steering wheel/pedals under acceleration.

The problem may be inside the transmission transaxle assembly bearings or in one of the wheel bearings. I recommend having a mechanic like one from YourMechanic come and diagnose the problem to verify and diagnose the problem. It may even...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...
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.