This bulletin applies to 2018 and prior Cadillac and other gasoline-powered GM vehicles. Technicians may encounter a concern where the catalytic converter has come apart or has set a P0420 and/or P0430. If you believe the catalytic converter has failed with no apparent reason, it is recommended to inspect for a poor crimp for the coil grounds terminal on the engine block for the bank with the concern. Inspect the grounds for possible corrosion or damage at the ground terminal ring, fasteners and grounding surfaces. If no corrosion or damage is found, tighten the ground bolt to the proper torque.
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 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.
