One of the causes for low oil pressure in a Chevy Tahoe could be a clogged or dirty oil filter. Changing the filter may get rid of the problem.
Low fuel pressure.
1999 Chevy table oil pressure gauge low and check gauges flickering
Run the ac for awhile, the low pressure hose will be the cold one that is sweating.
A bad oil pump, bearings worn to the degree where the oil passs through them too easy, or an oil that's too runny.
bad gas filter block or low fuel pressure
Low power steering fluid or you need a lube job.
Trouble code P0430 means: Catalyst System Low Efficiency (Bank 2)
The low side is always the big line on the a/c system. The little line is the high side.
Not sure, i would say oil pump or cam bearings
Usually you will not get an accurate oil pressure reading either too high or too low. Occasionally they will leak and pump oil through the switch
It is the key fob battery.
If a 88 Chevy Pickup Truck seems to be low on power the timing should be checked. The fuel pressure and fuel pump should also be checked and may be the source of low power in the vehicle.