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hey guys,

This is going to be a stupid question but i have to ask.

Where exactly is the downstream sensor for the V6 model?
I just replaced the two upstream sensors for front and rear bank but can't seem to locate the downstream sensor.
I've skated up and down my exhaust system 5 times on my new creeper that my lady got me for christmas ^.^ (side tracked) and can't see the downstream sensor =\
Would i be right to assume it is after the cat? would i also be correct in assuming there HAS to be one after the cat no exceptions?
I ran my hands along the exhaust pipe from the cat all the way to the muffler and nothing.
Am i just blind or is there a possibility that my 2000 MCV20R Conquest Wagon is without a downstream sensor?
 
isn't the downstream sensor always after exhaust manifold, but before flex pipe, usually at the bottom of the car? no exception on that.
For my 4 cylinder baby, the sensor was on the driver side of the car.
 
yes, on my ride it's after the CAT, literally on the exhaust section under the center arm console, the wire to it goes from socket under the driver's seat.

I'd say if your car has the cat then it should have the downstream o2 sensor since it's used for monitoring of the catalytic converter efficiency.

was your exhaust replaced at some point by any chance?

hey guys,

This is going to be a stupid question but i have to ask.

Where exactly is the downstream sensor for the V6 model?
I just replaced the two upstream sensors for front and rear bank but can't seem to locate the downstream sensor.
I've skated up and down my exhaust system 5 times on my new creeper that my lady got me for christmas ^.^ (side tracked) and can't see the downstream sensor =\
Would i be right to assume it is after the cat? would i also be correct in assuming there HAS to be one after the cat no exceptions?
I ran my hands along the exhaust pipe from the cat all the way to the muffler and nothing.
Am i just blind or is there a possibility that my 2000 MCV20R Conquest Wagon is without a downstream sensor?
 
hey guys,

This is going to be a stupid question but i have to ask.

Where exactly is the downstream sensor for the V6 model?
I just replaced the two upstream sensors for front and rear bank but can't seem to locate the downstream sensor.
I've skated up and down my exhaust system 5 times on my new creeper that my lady got me for christmas ^.^ (side tracked) and can't see the downstream sensor =\
Would i be right to assume it is after the cat? would i also be correct in assuming there HAS to be one after the cat no exceptions?
I ran my hands along the exhaust pipe from the cat all the way to the muffler and nothing.
Am i just blind or is there a possibility that my 2000 MCV20R Conquest Wagon is without a downstream sensor?
Part of the emissions regulations that drove to the OBDII spec were requirements for a way of gauging catalyst effectiveness. The downstream sensor is a way of meeting that requirement. The location is downstream from the primary catalyst, and the purpose is to make sure the primary catalyst is doing its job, and that you don't have an exhaust leak.

Thus, the location is going to be under the front part of the car - right after the 'Y' pipe on a V6. It also may signal problems other than catalyst, like a flex pipe that's leaking...
 
One way to know for sure how many and what kind (O2 or Air/Fuel) sensors your car has is to look at the emissions label. It's either on the underside of the hood or on the firewall. Here's an example below.

See where this one says "SFI, EGR, 2HO2S, TWC, HO2S"? 2HO2S = 2 Heated O2 Sensors; these are the 2 upstream sensors in the exhaust manifolds. HO2S = Heated O2 Sensor; this is the downstream sensor. If it had Air/Fuel upstream sensors, it would say 2A/F where it says 2HO2S.
 
Thanks for the replies.

I'll have to take a closer look tomorrow as i am almost certain there is nothing downstream of the cat.

Maybe my issue is that i am mistaking the secondary cat for the primary =\ since i am under the assumption there is only one cat...
Also i haven't checked for the sensor anywhere near the Y pipe.

Maybe if i find that emissions label it might shed some light.

I'll check back later with photos if i am unsuccessful in locating it.

Thanks again for the help!
 
OK bad news...

Can't find it.
I did however find a mysterious rubber grommet and rubber tube coming out of the passenger side seat area that appears to have been created for a wiring purpose but no longer has said wire (shown in image 1) PLEASE tell me that its not what i think it is :facepalm: because that would mean i have to get the threaded section cut and welded in by some nob head, and i promised myself i wouldn't let anyone touch my car after i got stung the first time!

image number two is a diagram i drew (on my phone so be nice) where 'A' represents the location of the upstream sensors. So where exactly is the downstream sensor supposed to be? i naturally assumed it would be located at 'F' but after combing the area i came up with nothing =(

:wtf::he:dunno::help:



 
I'm pretty sure that's the drain for the AC evaporator. Water condenses on the evaporator, collects in the bottom of the box it's in, and then runs out thru that rubber tube. If you've ever seen a water puddle under your car after running the AC, that's where it's coming from.

If it had an upstream sensor, it would be at "F" on your sketch. Did you find the emissions label on your car?
 
Ah so it's an ac evaporator, thanks for that *phew*
On the other hand it is not at F so I'm still at a loss =[
After i put everything back together with the new upstream sensors I'll scan it again and see what comes up.
If there's still an error for the downstream then ill probably have to get one installed.
I found my emissions label on my bonnet but all it has are the valve clearances and what spark plugs should be used =\
This is all very confusing for me, it was supposed to be a straight forward rnr, sheesh...
 
I just changed my o2 sensor literaly like 2 hours ago. I know most of the people are posting about the bank 2 but this has to do with the bank 1. I got a brand new denso. Had no problem removing the sensor but when I put it back I had to spray some lubricant to get the harbor freight oxygen sensor remover off the sensor. Anyways I gave it like an hour than started up the car. I reseted the CEL by just taking off the neg and pos connectors off the battery but something strange happened (there was a lot of smoke coming out of the O2 sensor I just put in when I started up my 97 camry 4 cylinder).. I know a lot of you guys are experienced. What recommendations would you guys make on the smoke? Should I run it for like 10 minutes..I know its real cold out here so I'm not sure if that has anything to do with it. Anyone had this happen in the past?? Just by what I see I think it might be burning out the lubricant anti seize etc but I'm not 100 percent.
 
it could be the spray lubricant you used burning off ... or the sensor is not installed tight (have you used the copper lubricant or something else on threads) or allows the exhaust smoke to pass through threads?

give it a while until car fully warms up. can you smell exhaust fumes under the hood? if not then it should clear up in a while.
 
Everything looks good. I let the car cool down started it back up and it seemed to have a white smoke which I guess is good and 7 of my codes disappeared so I just made the assumption that it was just the denso anti seize and lubricant I sprayed to get off the harbor freight oxygen sensor removal tool. I didn't torque the oxygen sensor to dealer specifications but did put it in sort of tight where it was in there good..I jumped from that to another project where I am attempting to take the egr valve off the Toyota to spray it down and clean the garbage off of it but I'm having trouble getting it off I already took apart a lot of the hoses but can't get those damn bolts off the bottom of the egr valve to separate it. I took a little break and this is my first time really getting deep in my car but I'll post up some pics as soon as I figure out how to post them and any suggestions please from those that are experienced..
 
good!

just make sure that the flanged washer was crushed (it takes nearly 32ft-lbs to do that), it will feel like it's tight and then it moves a bit more (that's when flanged washer crushes).

I haven't touched egr valve on V6 (there is something odd about it on my car, newer design or something), but it was very easy to remove on '00 i4, however I had to separate it together with the pipe going from back of engine ... went a little downhill from there, because my old valve didn't survive separating from that pipe (tried heating the bolts, valve got melted) ... anyways, I replaced it with a new one from dealer online, along with new washers and it's been good ever since :)
 
I'm looking into buying a good torque wrench.. If you have any links on a good spot where you can find torque specifications on different parts on a 97 camry 4 cycl I would appreciate that. Thanks Moderator here are some pics. First one is the oxygen sensor thats good to go. The next one is the egr valve there are 2 screws and 2 under bolts to remove to get it out. It's where the ice cream cone is at. Im going to start on it in a minute. Also if someone knows a good way to finish getting off the throttle body post it. I want to clean all the garbage off these parts. Here are some pics now.
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I followed the directions no pics still. Is there a reason why the pics aren't coming up
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You're not getting the link posted correctly. It should look like this:

 
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