Code P0420, loss of power and high fuel consumption?

EDITORALI86

MEMBER
2016 NISSAN ROGUE
2.5L
4 CYL
4WD
AUTOMATIC
66,000 MILES

My vehicle listed above consumes a lot of fuel and loses the power to drive. RPM goes up when I accelerate but the movement is slow for a few seconds then back to normal. RPM goes up during hilly roads. There was a check engine light for a few days and it went away by itself. I have an OBD scanner that detects a p0420 error if I accelerate more and drive. If I drive normally then there is no error. Also, when we have the P0420 error code, I noticed the O2S11 voltage is 2.255. Can you please explain to me the cause and how to get back the fuel efficiency and power? Acceleration is very rough and slow when we stop and accelerate again.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
42,959 POSTS

The Diagnostic Trouble Code (DTC) P0420 indicates a potential issue with the catalytic converter's efficiency in your 2016 Nissan Rogue. This code typically points to a situation where the catalytic converter is not performing its job of reducing emissions as effectively as it should.

Here are some common reasons for a P0420 code, as well as potential contributing factors to loss of power and high fuel consumption:

Catalytic Converter Failure: The catalytic converter may be worn out or damaged, resulting in reduced efficiency and increased emissions. This can lead to both loss of power and poor fuel economy.

Exhaust Leaks: Leaks in the exhaust system before the catalytic converter can cause inaccurate readings and impact the converter's efficiency. This could lead to a P0420 code and associated symptoms.

Here is a guide to help us see if the cat is working or it has come apart internally and is blocking the exhaust system which is common:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Here is how to change the catalytic converter out. Check out the images (below). Please let us know how it goes.

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