E
Elijah
I have a 98 Pontiac grand am with a 4 cylinder motor that misfires occasionally. Just replaced the spark plugs, coil pack is functional (reading 10k ohms) and the boots are in ok condition. The car misfires mostly between 45-65 mph, would like to get a general idea of what to look for before I shell out any more cash. No obd II codes are present, at one time random misfire code popped up along with evap non-purge and o2 sensor slow response but went away couple miles later. Thinking maybe lean fuel/mixture? or vacuum leak? But would like to know why only prevalent in this mile range? Any help would be appreciated.