A persistent Check Engine Light (CEL) after an engine replacement is one of the top searches on CarEngineGuru.com. While alarming, CELs usually indicate sensor, emissions, or calibration issues, not engine failure. A Check Engine Light after engine replacement is common and usually fixable. Proper diagnostics and calibration ensure the vehicle runs efficiently without unnecessary repa... https://carengineguru.com/check-engine-light-after-engine-swap-what-it-really-means/