2002 Chevy Blazer P0131 P0137 P0151 O2 Sensor Faults - Starting Issues and Power Loss

I own a 2002 Chevrolet Blazer with persistent trouble codes P0131, P0137, and P0151—all related to oxygen (O2) sensors. The vehicle occasionally fails to start and experiences significant power loss during hard acceleration, such as when merging onto a highway or passing another car. I've tested the fuel pressure with a gauge and it consistently reads around 55 psi—acceptable at idle but low for sustained driving conditions. Despite this, the engine should not be cutting out under load, which suggests an underlying issue beyond just fuel delivery. I have already inspected and cleaned the MAF sensor and air filter, both of which appear in good condition. The distributor cap, rotor, and spark plugs show no visible signs of wear or damage. The stored STFT values are +3 and +4 on each side, and MAP readings were stable at 29 inches of mercury. During a test drive at 59 mph and 4000 RPMs, the engine began to lose speed and RPMs started dropping unexpectedly—eventually reversing—until I reduced throttle pressure and allowed the transmission to shift up. Given these symptoms, I suspect an issue with one or more O2 sensor circuits, possibly due to wiring faults or signal interference.