Those downstream HO2S don't do anything as far as how the vehicle runs. They are just there to see if the CATs are doing what they are there to do.
Just one hiccup? And only in the back - nothing in the front?

Check engine light is not on? But it comes on when you turn the key to the bulb test position?

 

The Ford Mechanic told me to pull the o2's to see of the cats were clogged, since I'm losing more power up hill and smelling nothing, I'm gonna gave to say they're not clogged. Picked up new o2's 2day, but as soon as I got home it started raining, so hopefully 2mrw or Sunday I can put them in along with the new TPS.

The Check Engine light works, all to well. It lights up quite frequently after a heavy rain to show me a cyl 4 misfire, and is currently on with 4 codes for removing the o2's.

The hiccup feels as if it comes from the rear, when it hiccups, it doesn't happen every time, but the power loss does. The trans stays at the same gear, the whole time as I lose power up hill.

There are numerous posts on this all over the net, people have thrown, plugs and cops at it, new cats, and new fuel filters, to no avail. If the TPS doesn't fix the issue, I'm going to assume it's the fuel pump or fuel sender unit going. The fuel sender is on it's way, since it'll dance when I get gas, it'll jump up a 1/4 of a tank, then another 1/4 and then drop 1/8th, then do it over again, this is if I'm not doing a fill up. After about 5-10min it'll eventually level out. But this isn't it crawling up and down, the needle jumps, up and down. That just started 2-4 months ago, I don't recall exactly. I was just above E 5-6 weeks ago and got $60 worth of gas, it clicked off at $44.53 and got rounded up to $45 but that took the guy quite a few tries, and wouldn't take anymore, when I started the truck, the needle rose to just 3/4's without issue, but didn't go anywhere else.

 

Pulling the downstreams wouldn't tell you anything - they are after the CATs. Don't know if it would run with the upstreams pulled or not?

 

My o2's are in the cats dead center, I have manifold, to resonator to cats, on both sides. From what I was able to tell from different sources. Unless the sensors are in the resonators . . . and the cats are before them.

 

I thought you had pulled the downstream (i.e, after the CATs) sensors....... mybad.
I thought you had the stock two chamber Three Way Catalytic converters on there. I'm gonna back outta here as I'm not familar with that Super 44 system with the sensors in the center of the CATs.

 

Nah I just have a Super 44 Muffler not a full exhaust. Everything from the engine to the muffler is stock.

As an example this a magnaflow pic I'm using to explain only, this has the o2 sensor in between the cat and the resonator. My o2 is actually where the A is in Magnaflow on the cat. This would be the passenger side of my exhaust.

http://www.carsteering.com/data/all_images/45-01168.jpg

 

Oh, okay. But on your vehicle, where is your upstream HO2S and the downstream (the one you removed) O2 sensor?

BTW, here is a pic of a 2000 Ford Expedition (VIN 6 engine) two-chamber TWC Catalytic converter. Click to enlarge and you will see the bung for the upstream HO2S and the bung for the downstream O2 sensor.

 

My up streams are about 6-8" from where the manifold meets the block, right behind both front tires, can turn the wheel and touch them, the down streams are where the A is in Magnaflow, in the pic I posted, dead center of the cats. Other than the pic being full magnaflow, and the o2 being in a different spot, that pic is exactly what OEM looks like under my truck for the passenger side. I pulled both down streams, gonna put the new ones in 2mrw sometime, if I don't head to the shooting range. Was able to get 2 Bosch for $53 from Advanced via their site, with a $35 off coupon, ran there after work Friday and picked'em up. One had broken ceramic coming out and since both were the originals that came with the truck, as are the up streams currently. I'll replace those in a week or 2.

 

Ok so today I threw in the 2 new down streams, and cleared the codes on the truck. I hit the hill that always causes me grief and I didn't lose much of any power. I only got to the hill at about 2100Rpm's and I stayed at 49/50 the whole way up without having to hit the loud peddle all that hard. I'll see what happens throughout the week. And I'll be ordering new up streams, later this week.