Replacement AFM need tune?

[DONO]

Hey everyone, i recently bought a new AFM for my series 1 r33 GTS as im replacing the old one (suspected issues etc).

Quite simple, The old one is the original series 1 green label AFM, and I simply replaced it with a new series 1 green label AFM.

Upon putting the new one in, the car runs awful, worse than just running it without one plugged in.

Upon asking the seller, I was told the AFM needs to "relearn the fuel trims". I've not heard of this with any AFM replacement before unless its an upgrade to a different module, however this is just a direct replacement.

Is this right? And if so what would I need to do for the ecu to 'relearn the fuel trims'. (The car is non turbo, running pretty much everything factory )

[GTSBoy]

You can't do anything except disconnect the battery and pres the brake pedal for a minute or so to kill all power to the ECU. When you power it back up it will have forgotten its long term fuel trims and will start again.

This might help, or it might not.

The AFM you bought might be a nasty copy, and there is no guarantee that it has the exact same characteristic as the proper one. If so, it will never be any good.

There is no "tune" possible on that ECU.

[DONO]

Thanks mate I thought this was the case, I'll do that in the morning. Just wanted to see what others made sense of it, will update how it goes.