Some owners of 2007-2015 Mazda CX-9 vehicles may complain of a check engine light on while driving. If diagnostic trouble codes (DTCs) P2A04:00 (HO2S LH circuit range/performance), P2272:00 (HO2S LH signal stuck lean) and/or other DTCs are found, inspect the C-34 connector for engine oil contamination.
If contamination is found, inspect the engine oil pressure switch for external leaks. If a leak is found, replace the oil pressure C-34 connector and harness of oil contamination.
Inspect the relayed O2 sensors according to the instructions on MGSS online. If the related O2 sensors are not operating correctly, replace the affected O2 sensor(s). Clear DTCs and test drive to confirm the repair.
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Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety ofspecialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.
