Volvo: Emission System, mass air flow sensor, mass air flow

Question
I have a warning on the Dashboard saying "emission system service required" What does this mean been to two garages fault goes then comes back. Would this have an effect on the idle on the car. Volvo S80 2.9SE Year 2000.

Any help

Thanks Andrew

Answer
Hello,
it means your car has emission system has problem. It may have at the inlte side or at the exhaust side or both. At the inlet side, some sensors may have problem or at the exhaust side. At the inlet side, mainly mass air flow sensor, and electronic throttle module (ETM), and at the exhaust side there are oxygen sensors. All of them or some of them or another sensors related engine may have problem. If your car has idling problem, as a clue I can say that ETM may have problem. The car should be checked via VADIS(Volvo Aftersales Diagnostic Information System) in an authorised dealer. And the car should be repaired, as I can understand from your writings the Diagnostic Trouble Codes were erased, so the message firstly went and came again. It is not a solution as you can undestand it erases the message but since there is problem it comes again. So, to complete solution according to diagnostic trouble codes the solution should be found. If you can learn the codes from the dealer I can help you more...

Regards...