Why is my malibu idling hard while stopped at a red light?
two day ago i got gas. after getting gas my car starting to run hard when in drive and stopped. I put heat and injector cleaner in gas thinking it was water or trash causing the problem. my engine light came on and scanned it only error was a bad spark plug on 6. it seems to run smoother when in park but when in drive it idles hard. and has a ticking sound from motor. is this all from bad spark plugs, is transmission bad, is it a fuel pump, or a bad motor due to the ticking sound? I plan on changing the spark plugs and wires first but dont want to tear up my car driving it till i find out whats wrong. let me know what you think is wrong.