Can you monitor the live voltages reported by all 4 o2 sensors? (Ov all round right?)
My guess here is that something got missed in your install and the sensor wires aren't plugged in or powered further up towards the engine.

Trace the o2 sensor wires to see if everything is connected and report back. I'll take a look in rave tonight once the kids are in bed to see where the power is supplied from and how the o2 sensors all hook up into the main harness.

 

Not sure if this device allows for live feed of the o2 sensors, will take a second look tomorrow before I go to work. Unfortunately I dont know if anything was missed during the install as my mechanic did the work. I cant imagine why the wireing harness would have been removed though.

Unrelated I just ordered a new heater core. There is little if any information on the replacement process, but several posts on the forums suggest that the entire dash has to be removed. Nobody seems to be able to elaborate on this and afew folks have claimed they managed to remove and reinstall the heater core without removing the dash, but no details on how they did it. Looking at the rave page 1186, seems simple enough and does not mention anything about removing the dash. It does say that you first need to remove heater assembly and I believe by that its talking about the heater blower motor assembly. I imagine the glove box should be removed as well. Other than that is just says to remove some screws and remove the pipes connected to the core, replace core and refit everything.

If anyone has any information on the heater core replacement please share it here. Yes the previous owner used stop leak in the truck. Why? Because they did not know better and these stop leak products do not mention the harmful effects of using it on your vehicle....

 

you have an ultragauge still right ? If so, use it to look at your 02 sensors. it'll report 0v at all sensors is my guess.

it's so easy to miss something on an install. You want to be looking to see what the connection to the ECU looks like for the sensors. Did you check to see that they're plugged in ?

 

I have not had time to physically inspect the sensors but will do so this weekend if weather permits. Yes I still utilize the Ultragauge. Before recording this short video clip I warmed up the truck and took her for a good 15 minute drive through town, and let her idle for afew minutes prior. Here is the data for the o2 sensor live monitoring:

https://www.youtube.com/watch?v=pYEg...ature=youtu.be

 

Hey Julian. I had a bit of time to think about your problem.
Your error codes are all for the post cat O2 sensor heaters right ? Looking in RAVE, Fuse 2 under the hood controls the O2 heater circuit, not sure if it's all 4 or just the post cat ones, but definitely just check that to make sure its nothing so simple.

Do you know what brand of O2 sensors your mechanic installed into the rear ? I'd get underneath and have a look if i were you, in case something got missed hooking these back up. The wires can get chafed and cause this type of problem.

one last thought i'm hesitant to throw out, Catalytic Converters do have a limited life span. I do not believe that a bad cat would case this error though. My thought is that it "has' to be either the wiring from both sensors to the ecu or that both sensors have bad heater circuits.

 

I've been busy. Removed all the plastic covers from the engine bay and gave them a few layers of fresh paint.

http://i1201.photobucket.com/albums/...pspjadsc4r.jpg







Next I cleaned up the headlight's and applied a bead of weather proof silicone around the diameter of the driver side headlight assembly - water was seeping in and causing the inside of the assembly to fog up.

 

Many thanks to Abran Abeyta for a functional electric fan. Installation was easy and now I have a working fan



I also decided to flush out the heater core. Job was easy enough and water came right out as it should. The flush seemed to improve the heating quit a bit for about a week. But now its less effective again. Some days it blows hot air, other days, especially on really cold days its lukewarm:





I decided to make an appointment with DAP/Performance Unlimited in Bridgewater Corners Vermont; to diagnose the 02 codes, wire my rear work lamp and get an estimate on rust repairs to the frame. Turns out one of the cat back sensors was not fully plugged in (as some of you suggested) but they also found engine misfires. In some cases a faulty 02 sensor can trigger lean/missfires so I'm hoping the corrected rear sensors will resolve the engine misfire. Otherwise I will be replacing both the ignition coils.

There are some interesting vehicles here. Including a Defender 110 import with the 300 TDI. Its getting a full restoration from ground up, modern day computer systems and some modern cosmetic interior bits:

















I never thought a Defender would have this many wires...

 

Some pictures outside the shop:

 

So how much did this shop charge you to plug in your O2?
Why don't you just do this work yourself?

 

$230. They wired the rear work lamp and examined the frame rot for free