Hey Scotty,

What would be your initial thoughts if your "Low Oil Pressure" light came on, oil pressure gauge at 20psi, fuel gauge starts fluctuating (floating needle), and your "service airbags" messages all came on at once while stopped at a stoplight" Im thinking its electrical...brand new PCM/ECM (1 Year Old), full of oil and fuel, fresh oil filter. 2005 GMC Sierra 1500 with 205,000 miles. No codes or check engine light.

No. 1-1

My first stop would be AutoZone, request free Load Test of 1/ Battery; 2/ Alternator; 3/ Starter. If results are inconclusive, I'd probably buy my own Load Tester and check that trio again. Something is fritzing-out things across several of your systems. Next, I'd check that PCM-- did you buy OEM or aftermarket. They've been known to fail. Third, check relays, fuses for your ECM and PCM, etc.