Hi the Volvo dealership said I had a faulty MAF($411.00) on my 2001 S60 2.4t. I bought a new one from another source. I replaced with the exact same sensor. Before I changed the MAF the car was running good except I had a check engine light. Now the cars RPM surges while stopped and in drive. Can you help me with this? Is there a way to reset the check engine light as that was the only code I had? Do you reccomend premium fuel could this be the problem since I usually run regular. Thanks Sorry for also responding in the S-80 forum it was an accident.