you added 3 bottles at one time? is the car making any noises going up hills like rattling from the engine or any other time under load? you may have brought your octane way down with all the cleaner. pull your plugs check for fouling you added 3 bottles at one time? is the car making any noises going up hills like rattling from the engine or any other time under load? you may have brought your octane way down with all the cleaner. pull your plugs check for fouling

as for the coils if it never misfires then its not them or the plugs. could be sonething making the computer retard the timing. take it to auto zone or a parts place like that; have them check for codes sometimes they will be there without the light. the cpu stores all codes waiting for multiple faults before the light will come on as for the coils if it never misfires then its not them or the plugs. could be sonething making the computer retard the timing. take it to auto zone or a parts place like that; have them check for codes sometimes they will be there without the light. the cpu stores all codes waiting for multiple faults before the light will come on