hey guys, just need some advice here.
backstory:
few weeks ago put in a full tank of 98 safeway petrol
drove ~10kms to mates place, stopped car for 5 mins, started again...engine ran rough as hell which made the whole car rumble...engine light came on
babied it to a petrol station and put in some octane booster http://www.nulon.com.au/products/Fuel_Treatments/Pro-Strength_Octane_Booster/#.T74fL8Uya70
drove around for an hour, turned off car and turned it back on...light went off and car was smooth again.
next day, driving along and 2kms in orange engine light comes on again, car is rumbly like before...
figured alwell, must be the fuel...tank of 98 will help flush it out...
3 full tanks of bp ultimate later....light is still on and engine isnt running as smooth as before (not AS rumbly though)
100,000km service coming up as well...how do i fix this problem ?!
btw getting 370kms out of a full tank compared to a bit above 500 before
cheers, all help is greatly appreciated