Check Engine

[TreszPL]

I was pushing hard at closed road today(some sort of mini rally)and after a few kilometers when I was for about to stop at park lane i saw a check light(I didn;t look maybe for about 20 sec because I was talking with my co-pilot) I;ve turned off the engine and after a while when I've started up, now the idle is for about 1200/1300rpm and wtf? check light has turned off and everything seems to be ok, car accel.same as usually but more than often fire comes out the muffler when changin gear and braking with gears. I think maybe the bad quality of polish petrol can cause this problems? help please

[amigo]

hi,
you should run 100 octane fuel... if 100 octane is not available, you should use octane booster or remapped ecu.
What exhaust do you have? stock or decat?

your car may be running rich, this causes fuel being burned in the exhaust. Temp goes high and lambda recognize this and that's why check engine may come up.
maybe be related to MAF??? (No oiled filters should be used to prevent MAF problems)