what else can I do? I have had a tune-up, oil change etc. Wires and coil wires installed .
My car has 189000 miles.
My car has an automatic transmission.
Some of the things that a technician might suspect and decide to test on your Kia would be the cam timing (timing belt might have jumped), crankshaft position sensor function, engine compression, and fuel pressure.
Using a scan tool to check for diagnostic trouble codes might reveal something as well. If you need assistance with these checks, enlist a qualified mechanic who can diagnose the cause of your engine backfire. Once this is done, an accurate repair can be made to get your car running smoothly once again.