Understanding MAF part numbers

Only thing I posted on 3si I thought might be helpful over here LOL. Bob will remember this as it went on for weeks hahaha.


Hi All,

Not sure how relevant this is to most of you folks but I had some issues recently with my MAF.
I kept getting told by many very knowledgeable people that any MAF will work regardless of year or model. Every thread I read said the same thing. However...... my car is a JDM TT so what has been said on all these threads appears to be correct for USDM models ONLY.
I had some issue which I suspected was my MAF. So in all my wisdom I cleaned it with electronic parts cleaner. This made my car undrivable as it stumbled and lurched constantly. I cleaned it again and it came good for about a week. Then back to the same issues. Then one day it threw a CEL pointing to code 12 air flow sensor.
I bought a replacement going on the above rule that any version will work.
I had a 165 which I replaced with a 337. The stumbling issues was gone but now I had a different CEL. Code 25 this time Barometric Pressure Sensor. I had the seller send me another one just incase it was a dud. Next one was a 789. Same issue.
Ran through diagnostic process in the service manual and confirmed wiring is all OK.
Did more reading and searching on ASA/CAPS on both JDM and USDM versions and found the part numbers listed for both are the same.
I then had a light bulb moment and worked out what the numbers mean. The 3 digit number is actually the last 3 digits of the part number.

So:
165 = MD170165 [1st gen TT/VR4]
618 = MD183618 [2nd gen TT/VR4]
337 = MD357337 [NA]
338 = MD357338 [NA]
055 = MD151055 [NA]
789 = MD187789 [NA]

From this brainwave I realised the 2 parts I had tried are both from an NA version.

I then sourced another 165 and fitted it tonight and car is back to normal. No CEL.

So... moral of the story is. If you have a USDM 3S then you should be able to use any MAF version. However even 3sx sell a different part number per version so I would attempt to locate the correct part number.
If you have a JDM GTO then you MUST use the correct part number.
I can only assume this is due to the differnt ECU used. I am yet to check the ECU part numbers for Europe yet as I haven't installed EU ASA. Once I have done this i'll check back.

These are the threads I had running incase it's helpful to anyone.

Issues with using alternative MAF part number??

CEL Code 25 - Barrometric Pressure Sensor

Australia: Anyone got a 1st gen MAF spare?

Sorry about the length but hopefully it will help someone in need.

Cheers,

Joe

They might ohysically be the same parts etc but the rom or calibration is different which is non serviceable to the average person. I'm talking about running stock ECU etc. JDM ECU will ONLY work properly with the right part number. I have not tested my 1st gen TT with a 2nd gen TT so can't comment on that. But it most definetly does NOT work with an NA MAF.