can someone please give advice my subaru has jush had air flow meter replace and 3 months laster ive got the same symptoms when car is idleing the revs are dipping from 900 down to stalling point in jumping back up can anyone give advice on how to fix this or what could be the cause ??

 

It is possible that the MAF has gone faulty. If it's a 99/00 then they are particularly weak and if running an oiled induction kit can be prone to contamination. Could also be a VTA dump valve as these can possibly cause idle issues.

I have heard of a method of disconnecting the MAF when the car is warm and sat at idle. If the car stalls then the MAF is still sending what the ecu thinks is correct readings, if the car continues to run the the ecu is basically ignoring the MAF readings as it thinks it is faulty. Please double check with someone else before going down this route as I haven't tried this myself.

 

I read that too, about disconnecting the MAF and tried it on mine, it stalled, didn't do it any harm.

Could the Lambda be causing it?