240sx check engine codes

[miha82]

Hi,
I have a 1996 240sx 5-speed base (no mods, all stock), which recently started to display the error codes below:

P0100 mass airflow A circuit
P0325 knock sensor
P1445 purge volume control

The car drives ok most of the time; sometimes it staggers during the acceleration, but it does not happen too often.

The shop I went to recommended replacing all 3 sensors to resolve this (around $700 in parts and labor). They could not find anything wrong with the sensors themselves, wiring, etc.

Do you have any suggestions for troubleshooting this? I am not sure if just replacing all sensors is the best/cheapest way to fix this. Any help would be appreciated! Thank you in advance

[PapaSmurf2k3]

I'd start with trying to find a good known MAF and replacing it first. Reset the ECU (disconnect the battery for 10 minutes or so) after installing it, and see if the other codes come back.
Purge volume is dumb and shouldn't cause any performance issues, but a bad MAF can lead to the knock sensor tripping and performance/fuel economy degradation.