Some 2021-2023 F-150 vehicles equipped with a 3.5L PowerBoost engine may experience a loss of engine coolant with possible engine overheat and/or illuminated malfunction indicator (MIL). This may be due to a crack in the exhaust heat exchanger coolant spigots on the top of the exhaust heat exchanger. The exhaust heat exchanger coolant spigots are now released and should be serviced in pairs. It is no longer necessary to replace the muffler inlet pipe assembly for this type of concern. Workshop Manual, Section 309-00D has been updated to include a new service procedure. For claiming, use causal part 18663 and applicable labor operations in Section 05 of the Service Labor Time Standards (SLTS) Manual. Heat exchanger coolant spigots - NL3Z-18663-A (2 req).