Moved to southern Cal from Colorado. My FX35 has gone from awesome to sad??

ECM (computer) has control over changes in barometric pressures (altitude) and should adjust air/fuel ratio according.. Suggest full professional scan test.

Diagnostic charges will vary from shop-shop...but most will start with an hour of diagnosis time, or around $150 in your area. If you need a shop or dealer, please go here: https://repairpal.com/infiniti-repair-in-murrieta-california-92562 Good luck