First a little background. I bought my ‘05 Kia Rio from the previous owner after the hood came unlatched on the freeway resulting in a smashed windshield, flattened roof, destroyed hood, bent fender (he bounced off the middle divider) and damaged door. I’ve done all the body work myself. The car starts and runs good but has a little hesitation on initial acceleration and isn’t getting very good gas mileage. The check engine light was on and showing the code P0130 (O2 Circuit Bank 1, Sensor 1) DTC Severity 2 of 3). So far I have replaced the Upstream O2 Sensor, new spark plugs, wires, coil pack, air filter, oil and filter change, new battery, checked the exhaust system for leaks, checked for vacuum leaks, flushed the radiator, had the water pump and timing belt replaced and replaced the plug going to the O2 sensor as it was dry, cracked and showing wires through the insulation. The most recent things done were the water pump, timing belt and plug replacement. It is still throwing the same code and is actually running worse. Now when I give the engine a light rev and let off the gas, it stalls but starts right back up. So, my question is, does anyone have any suggestion as to what I should do with this car? Short of putting a .45 slug through the block? LOL. If I had any hair I would be pulling it out. HELP!