Changing spark plus on 99 Grand AM can't get at reat plugs to peplace car is misfiribg car has 123,000 miles on it the original 100,000 mile plugs are still there I believe te mis fire is the plug
Car is misfiring, engin light is on and i believe plugs are bad
Vehicle Parts & Accessories - Ngk - Spark Plugs BR4HS Plug 10/BX #3322
Answers & Comments
U need to replace all plugs and wires to correct your problem