Q: P2097, P0420, P0008, P0430, P0420 codes on Buick Enclave. Is this really just the intake manifold gasket?

OBD-II trouble codes do not constitute a diagnostic or identification of failed parts. The print-out that you received should have stated, "the parts referred to in these trouble codes must be actually tested on your vehicle to determine which parts, if indeed any parts, are actually faulty, that is an actual diagnostic must be performed on your vehicle. Do not replace parts solely because a trouble code refers to them." Trouble codes do provides clues (sometimes valuable, sometimes useless and thus irrelevant) to components, circuits and systems that might be related to the underlying fault. In your circumstance, to get those codes investigated and resolved, the recommended service is a Check Engine Light diagnostic. If you request that service, a certified mechanic from YourMechanic will download the trouble codes (to confirm them, but also to obtain the accompanying freeze frame data that is stored in the vehicle computer) and then test the relevant individual vehicle components and systems to pinpoint the cause of the fault. Once the EXACT cause of the fault is pinpointed, the mechanic will let you know what, if any, parts must be replaced, why, and at what cost. If you request the Check Engine Light diagnostic, the responding certified mechanic will get this diagnosed and resolved promptly, right at your location. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the BEST possible results.