whats missing?? Need some input

Hey guys. New to the forum, but have read quite a bit of helpful info on alot of old threads.

This is my 2nd toyota, but first time having oxygen sensor issues. I recently purchased this 2 owner, 01 tacoma 5 speed, 3.4L and it was in great shape. The CEL was on when i bought it, but it ran fine. Ive owned it about 6 months and since then, my gas mileage has gotten horrible, and it sometimes wants to almost bog down when at low rpms and movin slow up inclines. So the codes are reading banks are lean. I made a rookie mistake and went ahead and ordered both Denso sensors bc i assumed thats the issue. This evening, i figured i would go ahead and spray down the nuts with liquid wrench, so i put it up on our lift and i couldnt find the rear O2 sensor. Im not a mechanic by any means, but it didnt take me long to realize it looks as if they cut it out and straight piped it. (See photo)

So my questions are:
1. What all did they cut out? Whats missing?
2. What are the pieces hanging there and the hose to the far right?(circled)
3. What do i need to do to keep the CEL from coming on if the rear O2 is gone?
4. Whats the effects of not having the rear O2 sensor?

Ultimately, this is my daily driver and the truck is in great shape, so i want to take great care of it.. but id like to keep decent gas mileage and id like to have the CEL off, but still able to come on if theres other major issues.

Thanks in advance for your input!

 

Well I think that's where your catalytic converter used to be, and that part circled on the left is an exhaust hanger.

That's all I got. Sorry, not much help...

 

Dont be sorry. I appreciate the input. I had been reading on here that people had issues with the heat shield for the rear sensor, so when i seen the heat shield and nothing around it, i assumed they had the cut one of the cats out. Just makes me wonder if they done it bc it was clogged, or for some other reason. (Bought the truck from a widow.. so the truck had no mods or anything)

 

Yeah, it probably was rattling, that's why I replaced mine. They're not cheap, probably why they stuck a pipe in there.

I did put in a 49-state legal one instead of OEM. No codes so far, about 10,000 miles on it.

I wonder if the previous owner experienced those same symptoms and thought eliminating the cat would help.

 

the fact that the rubber hangers were cut off makes me think the cat was actually stolen. i dont think a person working on the truck would be that impatient on slipping them off.

since you already have the o2 sensor get a bung welded into the system. not having the o2 at all can give some weird codes.

 

Never even considered it being stolen, but that makes more sense because the truck is bone stock and well maintained.

So add the bung and then install the rear O2? I need to make sure the piece it would connect into is still therr somewhere, right?

Thanks!

 

connector should loom up over the transmission.

put the sensor back far enough so you can put a replacement cat in later if you feel like it.

 

Wonder what the rubber hose goes to on the far right?

 

Follow it. Dont think my truck has one there.

 

That rubber hose, at least on my truck, is the wire loom for the o2 sensor which goes straight up through the cab just under the passenger front seat.