Ok so what has been done to fix this:
new O2 sensors (all 4)
new AFM
all new injectors and seals
all new intake seals
sealed off the little intake nipple
new cats

It's allegedly a 4.6 block running on a 4.0 computer, and with the correct 4.0-4.6 AFM. Have to check block numbers.
I clear the codes, and she runs for 40-50 miles and then the 'check engine light' running a touch rich. Getting .585 on both front O2 sensors.

To do:
new brake booster manifold adapter
new H2O sensors

Any other ideas??? Thx

 

Check wiring to connectors on O2 and really look at the wires going into the connector.

Fuel purge valve could be sticking open sometimes

 

Your 02 sensors would read 1.0 if the engine was rich and they were working correctly. Actually, they are supposed to cycle between .2 and .9, you can't really tell if they are working unless you have a tool that will chart them. The cheapest is a elm327 off Amazon and the Torque App.

 

Thx for replies. I have only done x4 sensor 02 test on my OBDII scanner. I will check again with better unit. Wiring seems good. Will check again.

 

@Xrad the Torque App and the ELM327 works well for graphing o2 sensors, I used it to check mine. If are interested in that kind of scanning there are better ODB plugs than the basic ELM327