P0131, P0137, P0151

I have gotten these codes twice in one week and have noticed a serious decrease in performance. When cold the truck is fine and has all kinds of power, after warm up it hesitates, misfires and bogs down. If i take off hard or try to pass it bogs and misfires, till i back off the gas and baby it then it goes. i am at a loss, some tell me to replace o2 sensors others say it is something else causing the o2 sensors to report badly. the car has 78,887 miles on it. new puel pump about 15.000 miles ago. any help greatly appreciated. Oh yeah the vehicle is a 2002 chevy blazer LS 4X4 4dr with a 4.4l vortec in it. automatic tranny

Might be as simple as a dirty element in the MAF caused by an oil soaked
K&N air filter, might be a low fuel pressure problem or a injection assy issue, just because your fuel pump assy has only 15000 miles on it doesn't mean the filter isn't plugged or even that the pump is good.
check for proper fuel pressure and check to see if the pressure is bleeding off. Might be a blown fuse or wiring issue to the 02 sensors as well.

I'm having the exact same problems under the same conditions and getting the same codes on a 97 Chevy Astro.

Recently replaced: Spider Assembly, Plugs, Wires, Distributor, Fuel Pump, Fuel Filter.

Double checked fuel pressure, MAP Sensor, MAF Sensor. All showing normal readings.


It makes me suspicious that 3 O2 sensors could fire a code at the same time so I'm hesitant to run out and replace them until I elimate other possibilites.

Anyone have any other suggestions of what might cause this?