This is intended for 1998-1994 240SX
“Avoid using solvents that leave residues: like the aromatics [toluene, xylene]. Use electrical parts cleaner or Windex and a Q-tip to gently scrub the wires clean. Acetone, methelyene chloride or chloroform will also work well. (NOTE: It has been said that carburetor cleaner is too harsh to use).
Note: The Q-tip method is recommended only when the sensor wires are really dirty and simply spraying cleaner on them will not clean them. Be very careful when using a Q-tip! Use a Q-tip and gently scrub the wires.
If the MAF wires are not really dirty you shouldn’t need to use a Q-tip. Just spray the wires and let dry. If there is still gunk on them – use a q-tip to clean them. If you break a wire you are screwed. Do NOT scrape with anything. ” by Rogoman
(for the proceeding test , the maf is connected to ecu so you have to pull back rubber part at connector and insert tester probe)
2. with engine off and ignition in ON position, test between terminal 1
and ground . should read .2 volts
3.with engine on at idle, it should be 1-1.4 volts
There are 4 terminals on the plug 4 3 2 1
Another thing thats really important here is check that ground on your MAF make sure it is under .2 volts drop to ground