Loss of MPG?

MIKE**

MEMBER
2012 NISSAN ALTIMA
2.5L
4 CYL
2WD
AUTOMATIC
148,000 MILES

Went from 31 highway, to 18, city 22 to 15. I replaced plugs, air filter, and Master air flow sensor. It acts like it's missing but it's not. Its runs great has great pick/up and speed runs smooth but at city driving I can really feel the jerking.

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
42,959 POSTS

I can't tell if you are saying the engine is misfiring or not, can you take a quick video of the engine running I can tell right away what is wrong. Also do you have any codes? You can get a code scanner from Amazon for about $20.00.

Here is a guide/video to show you how:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is a scanner link:

https://amzn.to/3Qi1SS6

This guide can help as well:

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Please go over these guides and report back.

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Monday, September 12th, 2022 AT 12:16 PM

MIKE**

MEMBER
3 POSTS

Idles perfect, no misfires unless driving at slower speeds and you usually feel it when you let off the gas and it's jerks a little a couple of times.

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Monday, September 12th, 2022 AT 6:44 PM

KEN L

MASTER CERTIFIED MECHANIC
42,959 POSTS

Any codes? Most of the time when this happens is because the MAF sensor is off but not enough to trigger a code. Here is the location so you can check it out and replace the sensor to see what happens.

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