Codes are PO 420. PO 113 PO 302
P0420 HYUNDAI - Warm Up Catalyst Efficiency Below Threshold Bank 1...Possible causes; Catalytic converter deterioration or malfunction, Exhaust system leaks, Loose front or rear HO2Ss, Faulty front heater O2 sensor, O2 sensors harness is open or shorted, O2 sensors poor electrical connection...As the code description implies the P0420 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem. If the P0420 code is combined with other codes, try fixing the other codes first........P0302 HYUNDAI - Cylinder 2 Misfire Detected...Possible causes; Faulty spark plug 2, Clogged or faulty fuel injector 2, Faulty ignition coil 2, Fuel injector 2 harness is open or shorted, Fuel injector 2 circuit poor electrical connection, Ignition coil 2 harness is open or shorted, Ignition coil 2 circuit poor electrical connection, Insufficient cylinder 2 compression, Incorrect fuel pressure, Intake air leak...The P0302 code means that the cylinder 2 is misfiring or is randomly misfiring. Start by checking for intake leaks an if no leaks are found the next step is to replace the spark plugs on cylinder 2. If the problem persist more tests needs to be done to diagnose problem.
Most likely the catalytic converter failed (P0420) because of the misfiring (P0302). The P0113 is a problem with the air intake temperature sensor. HTH. -Jim
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