Car seems to idle real fast when starts up or will kinds jolt and shake alil bit. change spark plugs, but idels real fast and before changed plugs and cable it wouldnt allow me to accerate fast w/o jolting. have replaced map sensor, manafold gasket, and cadalac converter that needed to be done. any help or suggestions would be great. replaced all the plugs, it now makes a poping sound when started. still stumped i checked the plug firing order atleats 10x