2000 GC8 Air flow meter issues
 

Gday guys,I have a 2000 GC8 and before the holidays it was running dreadfull and flagged codes for 02 sensor and AFM I replaced the o2 with an NTK one and that's been fine.

Bought an Geniune Subaru AFM that was $320 or so,car ran ok for about a week then reverted back to surging again really badly Mainly within the first 10 mins of driving!?.I had fitted a Subaru Panel filter into the stock airbox when I installed the new AFM ,so its all just a few weeks old. Cleaned the AFM with the proper cleaner the other day ,it ran like magic for 2 days then reverted back to surging and Laggy type acceleration again.Checked the codes Via Diagnostic plugs and its flagging Code 23 again ( AFM)

Ive looked and looked and don't know whats going on ,the airbox lid was properly inplace and tight ,the filter looks still fine too.Ive had the car 2.5 years and never had an issue until this lot recently. Its really frustrating ,even buying genuine parts im still having issues

I've got a spare Autronic ECU in the shed somewhere.
Scrap the AFM all together.

I did some more investigating and seen a film of oil in the intake pipe and on the Panel air Filter!, so its either getting bad blow by from stuffed rings or my PVC Valve is clogged