Volvo Repair: 1998-S90 Ethanol gas & CHECK engine, ethanol gas, volvo owner

Question
I filled up the tank (70 liters)with Ethanol gas(10% ethanol in gas - acceptable according the Volvo owner book) and soon after the engine idle speed start to act irregulary (misfire). After about 100 km, the CHECK ENGINE light goes ON.
If I purge off the ethanol gas I will solve the problem? Any suggestion?
Tks

Answer
Hello Raducu,  One of two things are happening,one,the oxygen sensor is making the mixture too rich or too lean.Two,the engine controls need to re-learn the adaptive functions to the fuel.Too much oxygen in the exhaust stream tells the o2 sensor to 'Richen up' the mixture,thus flooding the engine with too much fuel(letting the individule injectors spray longer),setting off the 'lite'.I would try the purge,however you will need to 'read the codes' and re-set the lite to realy go back to 'square one'.'Oxygenated fuel' by nature will 'over oxygenate' the exhaust stream. Thank you and good hunting!  PKD