# Rough idle



## Derekfleming777 (9 mo ago)

When my 2011 altima is in gear it shakes bad. Code reads mass air flow but I’ve changed it and the plugs and coils still same. Any ideas


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## VStar650CL (Nov 12, 2020)

Did you perform an IAVL on it after changing the MAF? Also, if the code was P0101, that's a "catchall" code which the ECM uses when it has an induction problem that it can't figure out. I personally have never seen it caused by a bad MAF. The most likely causes are:
1) Dirty Throttle Body,
2) Bad PCV Valve
3) Bad A/F (front O2) Sensor
4) Old ECM firmware
In the case of your '11 Altima, there's a Nissan service bulletin for an ECM reprogram, NTB12-051k : 


https://static.nhtsa.gov/odi/tsbs/2016/MC-10119172-9999.pdf


However, since you're having performance issues, one of the other causes is more likely than the firmware.


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## rogoman (Dec 16, 2004)

Derekfleming777 said:


> When my 2011 altima is in gear it shakes bad. Code reads mass air flow but I’ve changed it and the plugs and coils still same. Any ideas


When the tranny is in park or neutral, what is the idle speed and does it idle smooth? It should be around 650 (-+ 50) rpm.

When it's in drive, what is the idle speed? If it's way down from spec. An IAVL procedure may fix it.


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## cngarch (Sep 5, 2018)

Derekfleming777 said:


> When my 2011 altima is in gear it shakes bad. Code reads mass air flow but I’ve changed it and the plugs and coils still same. Any ideas


AC Compressor bearing, Torque Convertor, Transmission solenoid idle switch.


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