In theory, the D-Jet system should be able to compensate for the altitude change. To make a long story short: Check and replace any / all vacuum lines, fittings etc related to the engine, MAP line etc.

Then, verify timing, wires, plugs and gap etc.
Then verify the valves are adjusted properly.

Then (and only then), after verifying the injection system, ignition system and mechanicals are all 100% would you (or a mechanic) use a CO meter to analyze the exhaust and adjust the MAP.

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

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1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k