116 O, R Engine coolant temperature higher or lower than expected
213 R SPOUT circuit open
172 R, C HEGO (HO2S) sensor fault/lean
311 R Thermactor air system/fault during engine run self-test
327 O, R, C EGR valve position circuit below minimum voltage
411 R Cannot control RPM during KOER low RPM check
542 O, C Fuel pump secondary circuit fault

Problem Is: Very poor fuel economy, Stutters while driving (Not accelerating)

Can somebody point me in the right direction. Front tank fuel pressure is about 45psi @ idle. Error cod 542 because rear fuel pump disconnected and capped to prevent cross filling. 213, the spout connect is in, verified continuity through connector but not wiring to computer, what to do?

 

I know this is an old thread with no posted answers, but were you able to figure out your problem? I'm having similar issues with my 1995 I6 4.9L 5 speed. I'm getting the following codes that you had: 172, 213, 311, 332.

 

Considering its a year old and id guess he already fixed the issue...or sold the truck
as for your issue sounds like a fuel pump to me, couppled with a few emmisions issues. the egr is a very common problem for these trucks ive had mine replaced 2 times hoes replaced ect still has the egr valve stuck open code and its all new parts its just not working right and i dont care after it came back on.

 

What is engine vac at idle? Does it idle high?

 

It can throw false random codes after disconnecting rear fuel pump. First disconnect the battery. Remove on-dash fuel selector switch. Disassemble and check contacts. If the contacts are blackened, sand down the contacts lightly and check both springs for proper tension and seating.
Reassemble and reinstall. Connect battery.