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Home >> Jeep >> 2017 >> Wrangler Sahara, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 106 (2.4L - DTCS P0339 To P0632) >> DTC Troubleshooting >> P0420-Catalyst System Efficiency Below Threshold Bank 1 >> Possible Causes

Possible Causes

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
Possible Causes
EXHAUST LEAK
ENGINE MECHANICAL CONDITION
AGING O2 SENSOR
CATALYTIC CONVERTER

Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding. Refer to  PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE  .