Car jerking forward when at stoplight

Hello, "Fuel Injection Cleaning" -- this is unnecessary and could even inspire problems. What method of "fuel injector cleaning" was used? Typically this is "upsold" by repair technicians and has little or no actual benefit. However, it can richen your exhaust stream so much that you can damage your catalyst, for example. On the other hand, yes, diagnostic testing is needed to see what's going on with your Kia. One other thought -- were the coils replaced? Or just the spark plugs? Often times if you remove the coils, they will leak spark going forward and can cause the jerking you describe. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops