The Chevro

Hey guys, so here is the nitty gritty
Loss of power and horrible idle for about a month now

In an attempt to repair I did some regular maintenance first:
- I replaced the plugs, wires
- Cleaned the MAF
- Checked vacuum leaks and pressure (26psi IIRC) drops to .07 on WOT and bounces back (not sure if the WOT reading is normal)
- Checked for broken wires and grounds
-Checked fuel pressure 61psi with key on and 56psi idling. I just put the new pump in about 6 months ago......she left stranded

Codes:
P0131 - O2 sensor circuit low voltage / bank 1 sensor 1
P0137 - 02 sensor circuit low voltage / bank 1 sensor 2
P0151 - 02 sensor circuit low voltage / bank 2 sensor 1
P0154 - 02 sensor circuit no activity / bank 2 sensor 1
P0157 - 02 sensor circuit low voltage / bank 2 sensor 2
P0174 - System too lean bank 2

I've got two theories but no thoughts on diagnosis. First I was thinking my injector spider assembly may be leaking, and 2nd my uncle had a similar issue with his K1500 and it ended up being his cats were stopped up

Any help would be AWESOME!
Thanks in advance!

kevinkpk

That'd be my thought. You state the "vacuum" is 26 psi. That should be reading vacuum in inches of water column. 26 " of water column is very low even at altitude, with a rise of .07 " h2o is imo plugged exhaust.

The Chevro

I'm not totally up to par on the basis behind the reading except that my OBDII reader shows that value for vacuum in mg I believe is the acronym. I was running it on the fly to see what kind of readings I was getting. I spoke with a mechanic friend after running the test and he stated that 26" was normal, but with my lack of knowledge with vacuum there could have been some miscommunication there. Furthermore, he doesn't work for a dealer or anything, he owns a custom fabrication shop hooking up hotrods and custom welding applications. His knowledge may not be suitable for my specific application.

The Chevro

Regardless, with your input I have been contemplating gutting my cats and modding the O2 sensors as I have no emissions here where I live. Not to mention lack of $. The old burb is pushing 325k miles so I do some traveling.....

kevinkpk

Well, manifold pressure has always been measured in inches mercurey (My bad, atmoshpere). I can make about 26" with my 455 at idle, but she is 180K and 47 years old. I'd still regardless say with what you post plugged exit/cat

The Chevro

Thanks for the input, with that hopefully in the morning I'll gut them bad boys and if the issue is resolved I should get a whole bunch of power back. A little back story to the issue is I pull a travel trailer which is about 8k lbs and here in VA the largest mountain I experience normally is Afton which I'm not sure of the grade but I can usually pull it at 55 to 60mph.....once the engine light came on and the bad idle started I'm lucky to reach 40-45mph. I'm stuck with the tractor trailers and hazard lights, lol. Either way, thanks a bunch and I'll be sure to pop back on here after I perform some magic and reset the codes.