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1999 Kia Sportage P0422 and P0116 Codes: Check Engine Light, Gear Shifting Issues, and Sudden Acceleration

Model: 1999 Kia Sportage Fault Code: P0422 Posted: 2007-10-18 12:52

I own a 1999 Kia Sportage that has been displaying the check engine light. A scan reveals both P0422 (Exhaust Catalyst System Efficiency Below Threshold - Bank 2) and P0116 (Coolant Temperature Sensor 'A' Circuit Range/Performance). While driving, I occasionally experience gear shifting problems—feeling like the transmission isn't responding properly—and at times, when I accelerate, the vehicle suddenly surges or seems to take off unexpectedly. Any advice on diagnosing these issues? Could the P0422 code be related to a failing catalytic converter or sensor malfunction?

Related fault codes

P0422

Comments (3)

Anonymous 2007-10-18 13:26

There was a known recall for certain 1999 Kia Sportage models due to corrosion in the main intake manifold connector, which can trigger multiple intermittent codes. I recommend inspecting that connector for signs of rust or poor contact. If it appears intact and clean, then further diagnostics should focus on the catalytic converter and coolant temperature sensor. Did your check engine light come on suddenly or has it been flashing intermittently over months or years?

Anonymous 2007-10-18 17:55

The check engine light has been on for about a year, mostly steady but occasionally turning off for short periods—like one to two days after a tune-up. It seems to return quickly afterward.

Anonymous 2007-10-19 16:35

Given that the code persists over time and returns after maintenance, it's likely indicating a failing catalytic converter or an issue with the coolant temperature sensor. A proper diagnostic test for both components is recommended to confirm the root cause.