wdemko

I have a 2007 Rx350 with 65000 miles, warantee long dead. I've been on a long fruitless search for info on fixing a naggng problem with the dreaded Check engine & VSC lights. Its not a loose gas cap, so no need to go there! Got the code read at Advance Auto a month ago: P2195: Bank 1 O2 Sensor#1. I looked thru the posts on this and other sites, and was suprised to not find too much definative info on exaclty where the B1S1 was physically located. I still have not ever found a good picture or diagram of where this sensor is.

I did find the B2S1 on top of the manifold right when you open the hood, and thru the various posts was led to believe my problem was the sensor under the car, on the exhaust pipe just before it bends back towards the rear. I was able to order it at Pep Boys for $120. It was an identical looking part, and was even stamped "Denso" even though it came in a Bosch box. Put it in and had the OBD codes cleared. The lights came back 2 days later.

Drove some 200 miles with the lights still on, and had them cleared again. This time they came back the next day in only 21 miles. I crawled around under the car again and I put an ohm meter on the two I now know about (and the old one I pulled out) and I get ~15 ohms on all three - seems to be nothing wrong with the one I pulled after all. crap, After struggling to look around again I found that the one I replaced was actually a second one on the front exhaust manifold, under a little "bulged" section on the pipe. There is a second larger "bulged" section further down the main exhaust pipe back near the muffler, that I would have figured to be the catalyst, but there are no sensors aft of it... ??

I also finally found where the rear manifold is hidden way up with its own litle "bulged" section and a sensor after it.. No signs of a sensor above that bulge though, and seemingly no way to get to it it there were.

Now for the questions: are those two smaller bulges the catalysts, one on each manifold? If so, then is the larger one on the main pipe yet a third catalyst??

Is the sensor above each bulge know as #1, and one below #2? And is there one hidden above the second (bottom-most) manifold, or is there only one after the bulge for bank 1???

I really need a good picture or diagram that illustrates all this - I have run into nothing that is any help anywhere. If anyone has anything usefull please let me know.

RX330inFL

You might want to check with the dealership to see if your vehicle is covered by the following TSB. It may not be the O2 sensor.

Make : LEXUS Model : RX350 Year : 2007
Manufacturer : TOYOTA MOTOR CORPORATION
Service Bulletin Number : L-SB-0109-09 Date of Bulletin : SEP 02, 2009
NHTSA Item Number : 10032515
Component : ENGINE AND ENGINE COOLING:ENGINE
Summary :
LEXUS: ENGINE CONTROL. SOME VEHICLES MAY EXHIBIT A MIL ON DIAGNOSTIC TROUBLE CODE (DTC) P0138 AND/OR P0158 (OXYGEN SENSOR CIRCUIT HIGH VOLTAGE BANK 1 OR 2). IN SOME INSTANCES A P2195 OR 02197 (A/F SENSOR SIGNAL STUCK LEAN) DTC MAY ALSO BE PRESENT. CAUSED BY INCORRECT AIR FUEL RATIO SENSOR RESPONSE. *PE UPDATED 6 /28/10. *PE

wdemko

How do they handle this TSB type of work - is it considered similar to warentee work, in other words no charge even when out of warentee? I do try to stay away from the local dealers as, in my opinion, they are total rip-off artists and charge way too much for services.

RX330inFL

No, TSB's (Technical Service Bulletins) are just advisories for the dealers regarding various problems in given circumstances and on certain vehicles. Sometimes they are even more specific as to a given range of VIN numbers affected by the TSB. Once the warranties up are there is little to no chance you would get the needed repair done for free. However, it is a starting point and you could possibly talk to the dealership to find out what all is involved regarding the service for that TSB so you know what parts may be involved.

You may replace that O2 sensor you are trying to track down and find out that the error code just comes right back after you clear it.

lexusfan05

It may also be covered under emission warranty, which is usually 96 months/ 80000 miles. Check with dealer.

thomas1

The sensor you got may not be a good sensor, Go on Amazon and get one there made by denso....The Bosch makes me nervous as many have had problems with them. Also check your oil level make sure you are not over-filled. Apparently this can cause that code to be thrown due to foaming in the engine. This was reported on the Toyota Nations site by many....

mitsuguy

iTrader: (2)

Problem is, it sounds like you replaced the wrong sensor...

B1S1 - bank 1, sensor 1, before the cat on bank 1
B1S2 - bank 1, sensor 2, after the cat on bank 1

B2S1 - bank 2, sensor 1, before the cat on bank 2
B2S2 - bank 2, sensor 2, after the cat on bank 2

From your description you replaced one of the downstream, or after the cat sensors, when your code was for an upstream, or before the cat sensor... You found one of the Sensor 1 locations, but there is another on the opposite side of the engine, generally after the 3 to 1 exhaust collector, right before the primary catalytic converter...

wdemko

Yep Misuguy hit the nail on the head - I did replace the wrong one! Just could not even see the one above the "bulge" on the firewall side...

So, If I'm hearing you correctly this car has 2 (or more?) catalytic converts? One for each bank of three cylinders just below the manifolds? (the “bulges” I speak of).

Is that a third catalyst also along the main exhaust pipe, about twice the size of the others? It sure looks like it could be one, as you can see what looks like a geometric pattern on the metal exterior where something is definitely being held inside.

wdemko

As a note to all who follow this, the comment from "Lexusfan05" about being covered by the emissions warrentee:

At least for the 2007 Rx350, the emissions warantee is only applicable for the first 8 years and 80,000 miles for only a handfull of selected components! There were only about 5 items on the whole list that this applied to - the rest used the standard warantee. The sensors are NOT on the 80k list!! Go figure.

Still looking for that thing, maybe I'll find it this afternoon. ..

mitsuguy

iTrader: (2)

Correct, here is the actual text of the law:

http://www.epa.gov/oms/consumer/warr95fs.txt

Everything emission related is covered under a 2 yr / 24k mandatory warranty (for those manufacturers that don't provide a better warranty), and major components are 8 yr / 80k... Major components are the ECU/ OBD computers and the catalytic converters...

After reading that again, It would appear if you don't live in an emissions area, they might not be required to perform the repair, but, it would also seem that most dealers go ahead and do the repairs regardless...