2002 Rio Cinco
2002 Kia Rio cinco with 125,000 miles. I was experiencing a light hesitation on acceleration and during idle it would "hiccup" briefly. This turned out to be a misfire. I thought it was an idle issue so I cleaned the throttle body and IAC but it didn't fix the problem. Many people suggested fuel filter, bad gas, fuel injectors clogged, coil, vacuum leak, TPS, on and on... My plugs were 2 years old and my plug wires 8 years. I replaced the plugs and noticed it was slightly worse so that indicated that I might be on the right path. I ordered Korean made spark plug wires off ebay and measured the the resistance of the old and new wires. The old wires had 30 times more resistance than new ones, and after installing the new ones, the car running right again.