1998 P chassis problem with O2 sensors

[BobKomar]

I am working on a 1998 Bounder 34J with the 7.4L engine. It has 48,000 miles, and has the Banks power pack.

It has a loss of power and is giving P codes for all 4 of the O2 sensors being low voltage. It has not lit the MIL/check engine light.

I am thinking that all 4 of the O2 sensors dieing at the same time are slim. I plan on checking the fuel pressure to make sure that is close to the specs I can find. I think I should check the mass air flow while I'm at it. If they check out I'm going to get under and check the wiring to the O2 sensors and voltage present.

Any other Ideas of what I should check? Any place I can download a chassis manual that would cover this year?

Thanks, Bob.

[garyedgecomb]

Hope you found the problem. If not here is the solution. Its a bad connection in a block connector. I had the same problem. It drove me nuts and cost me a fortune in gas to find it since it would only loose power after it ran for long enough for heat soak to set in. I took all connectors apart, stuffed them with dilectric ( non conductive ) grease and then connected and disconnected them multiple times