uvachief

I own a 97 Chevy K1500 Silverado Z71 4x4 extended cab pickup with the 5.7L V8 vortec engine. It has nearly 202,000 miles on the odometer. At 199,000, the engine failed and I had to have it rebuilt. I also rebuilt the transmission at the same time. I got the dreaded P0137 error code and replaced all the oxygen sensors. I've rese the timing. I did the ECU drain by disconnecting the battery terminals and tying them together for 15 minutes and then reconnecting to the battery. I can drive for about 20 miles getting up to 60 mph and notice no issues. I then stop and fill up with gas or something. On the return trip, I get about 4 miles and it throws the Service Engine Soon (SES) code. The engine suffers a loss of power and sounds like a jet engine when you press on the accelerator after this happens. I also have intermittent AC problems when this happens. The AC will go out and come back on. The air flow will get real weak into the cabin as well. It keeps throwing the P0137 code, 02 Sensor Circuit Low, Voltage Bank 1, Sensor 2. I've now replaced all 4 oxygen sensors. Both upstreams and both downstreams. What the heck is making it still throw a code and what does the loss of power/jet engine mean? I replaced the fuel filter thinking it was struggling to get gas. I cleaned the fuel system and catalytic converter. When I reset the ECU, the truck drives and shifts like new. However, drive it until she is warm, cut off the engine for a couple of minutes and then restart it, you will get that code within 4 miles and the engine loses power. Any ideas what is going on?

Gumby22

P0137 isn’t setting because the oxygen sensors are bad - it’s an indication that the air/fuel mixture is leaning out when the demand for fuel is increased (stepping on throttle or increased engine load, such as climbing a hill with the cruise control set).

The reason the AC and blower are cutting out is because the PCM is disabling them to preserve electrical power for the engine.

Resetting the PCM only clears the code - it doesn’t resolve the reason why it’s setting.

This sounds like a problem with fuel delivery.

If your scanner can monitor live data, observe the short and long term fuel trims while the problem is present - if either value is in excess of +20% the PCM is attempting to add more fuel - if either value is in excess of -20% the PCM is attempting to reduce the amount of fuel.

The next step will be to check fuel pressure while the problem is present to determine if the fuel pump, regulator or injectors are at fault.