GMC Acadia low power and engine shut off while driving after catalytic converter replacement and multiple electrical issues on GMC Acadia

Some GMC Acadia owners report experiencing issues after replacing the catalytic converter, such as low power and engine shut-off while driving, along with various electrical problems. These issues may manifest as limited performance at higher speeds, irregular engine running, and unusual exhaust gas odors. Additionally, some owners notice a persistent check engine light, which could be due to sensor malfunctions or installation errors, as well as a drop in fuel efficiency potentially caused by improper alignment or back pressure issues. It is crucial for drivers to be aware that a replacement catalytic converter requires a proper "break-in" period to avoid adverse effects on the substrate, which could lead to converter failure. Furthermore, a catalytic converter code does not always indicate a faulty converter, as underlying issues like worn spark plugs, clogged air filters, or leaky injectors can also contribute to a loss of converter efficiency. Therefore, it is advisable for owners to thoroughly diagnose these potential problems to ensure effective resolution.