I have a 94 geo prism with over 200,000 miles on it,it has ran just fine up until today,i went and put in 89 octane gas in it when i normally would put 87 and it all of a sudden started being reallyh loud and shakes a bit while driving on the freeway like it wants to die but doesnt.

Cars & Trucks - Geo - Prizm - 1994 Geo Prizm