Inspect your spark plugs as described in section 8 and replace them if necessary. Also check all ignition wiring and components to be sure they are not cracked, worn or CAUTION damaged in any way.
Kia Niro 2017 (DE HEV) Service Manual: Rear Upper Arm Repair procedures
Removal
1.
Disconnect the battery negative cable.
2.
Remove the wheel and tire.
Tightening torque:
107.9 - 127.5 N·m (11.0 - 13.0 kgf·m, 79.6 - 94.0 lb·ft)
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Kia Niro 2017 (DE HEV) Service Manual: Spark Plug Specifications
Specification
Item
Specification
Type
ELR9ISP8+
Gap
0.7 - 0.8 mm
(0.0276 - 0.0314 in.)
Electrode Material
Iridium
...