Some 2017-2018 Ford Fusion vehicles equipped with a 2.0L gas/electric engine may exhibit an illuminated MIL with DTC P013A in the PCM. This may be due to an exhaust system leak.
Exhaust leak inspection should be conducted before performing powertrain control/emissions diagnostics. Inspect for carbon soot/moisture witness marks at exhaust connections and welds, including catalyst monitor sensor (CMS) boss, flex pipe and flanges. Inspect the CMS threads and crush washer to confirm that the sensor is fully seated in the pipe boss.
Do not use a Vacutec smoke machine to diagnose sensor leaks. Applying soapy water to exhaust connections while exhaust flow is restricted at the tailpipe and the exhaust system is pressurized at 5 psi will increase the ability to identify leaks.
About the Author
Information courtesy of Mitchell 1
Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.
Mike Mavrigian
Motor Age Editor
Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of specialties, 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.