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Discussion Starter #1 (Edited)
Thanks to my.is member dasgalloway for this picture and sophiesleeps for the original tutorial this was based off of.
In one simple picture.

SophieSleeps had posted this a while back with wiring diagrams, thought I'd follow up with a picture since I fixed one today. To confirm, all we did was cut/tap 1 wire to another.

Image shows what to do to fix a P0161 CEL on a 2002+ Is300.



To fix a P0141 (B1S2 Heater malfunction), all you have to do is switch which wire is cut and which is tapped, so instead of cutting red and tapping to green, you cut green and tap to red.

Enjoy!
 

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I'll do this, but I guess my question is what are the downsides to this? Will the O2 sensor wear out quicker due to not having the proper heating? Doesn't heat play a major role in the accuracy of this meter (that's not really a question since it does :p )?

Anyone list some downsides/side effects?
 

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Discussion Starter #5
under the hood, under one of the plastic covers
 

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What if both are having heater malfunctions? :|
 

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Discussion Starter #7
What if both are having heater malfunctions? :|
you need to be able to tap into one or the other, if both are malfunctioning than you need a new o2 sensor.
 

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you need to be able to tap into one or the other, if both are malfunctioning than you need a new o2 sensor.
I have it tapped the same exact way you have in the picture. However, the only code I'm throwing (with o2sim installed), is P0141. So I removed the B1S2 o2 sensor connect and used a resistor there instead to simulate the heater signal. I got the same code still. This time around, I spliced the actual wire and tapped the resistor into the heater wires instead of on the connector. I won't know if this will fix it but will have to drive a day or two to find out.

I was wondering if the method I'm doing is correct? It's the only code left. I used to have a lot of codes but the O2sim took care of those.
 

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I Dont Understand

I checked the code today on my 2003 Lexus IS 300 and I got code p0037. Everwhere it says that's bank 1 2nd o2 sensor. That's the one closest to the front of the car, not the firewall, but on this site it says p0041 is that sensor, bank1 sensor 2. So what is p0041 and code I'm getting? What is p0037 then?
 

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Discussion Starter #12
Bump

I have the bank1 sensor 2 failure on 2001 IS 300, too..
Will this trick work for the 2001 model? =)


Thx
The same concept can be applied to the 2001, however, the harness is slightly different. You want to tap the b1s2 heater signal to the b2s2 heater signal. Use this diagram for which wires those are:
 

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I'm seriously contemplating doing this for short-term fix to get an inspection sticker (P0161 B2S2 Heater Circuit DTC failed), but I would never want to leave it like this long term... There has to be decreased O2 sensor life...
 

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I'm seriously contemplating doing this for short-term fix to get an inspection sticker (P0161 B2S2 Heater Circuit DTC failed), but I would never want to leave it like this long term... There has to be decreased O2 sensor life...
Oooooh oooooh oooooooh, I got a quick fix... when you find those two wires (and, yes, this is serious) just cut up any extra wires you have in your garage (if you're like me and have extra wires everywhere) and just stuff it in each pin socket... it still transfers the same amount of energy (I honestly didn't think it would but it did). I did this the day before I got my smog check and i actually STILL have it in the way I described... don't cut your wires ,especially if it's gonna be temporary.
 

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Someone Please post a fix for a 2001 PLEASE!!!!!

I have installed an O2 sim but still get a CEL of PO161. I thought the O2 sim would solve the problem but I still have a CEL for B2S2, soooo Annoying!!!!

I have Megan Racing headers on my car and I had a CEL for B2S2, so I got myself an 02 Simulator and wired it in. Right away, the CEL went away but came back about 3 miles later, I cleared it and once again 3 miles later it came back on. I left all the sensors in the exhaust. Did I do something wrong?
I am having a similar issue. I have an 01 IS with PLP intake, OBX headers and downpipe, and HKS exhaust. I started to have the CEL after I replaced my headers and did some research and ended up buying the O2 sim from o2simulators.com. I had my mechanic install it and the part lighted up properly. I tooo started to drive off and with a few miles the CEL came back on.

I am not sure if for an 01 you have to solder in the 25watt 20ohm resistor as stated by

"ElitistK
300iss: If we ignore the heater circuit, then the CEL would still come on.
I wire a 25watt 20 ohm (or more ohms if you wish) to my heater circuits."

and where exactly does that solder into, inbetween the wires or somewhere else. I just need clarification if anyone can help please

Also if the above DOES NOT have to be done the only thing I can think of is switching the two WHITE wires from the O2 sim from one side to another. I really don't know if that makes a difference if anyone can clarify. Like I said the unit lights up every 2 seconds and flashes green and then goes out 2 seconds and repeats the cycle. I am 99% sure I installed it correctly but that is the only thing I can think of that I can change in my installation. I have researched this thread and many others and haven't seen a full clarification if it makes a difference from one white wire to another (basically switching B1S2 and B2S2 white wires on the O2 sim.

The only CEL that I receive is PO161 - "O2 Sensor Heater Circuit (Bank 2 Sensor 2)

Whats making me real upset is that I installed it almost a year ago and I thought after I tried the O2 sim and that didnt work I would just give up and deal with looking at my CEL everyday. But now I have to check and clear my CEL about once a month just to make sure that this is the only REAL cel code that the car is showing. Its been on my todo list for a while and I finally have some free time to take care of it with YOUR HELP.

I know that having this CEL on all the time is messing with my fuel economy and performance and just want to put this one to rest after all. I wish I was rich and didnt have to care about gas prices but please help a brother out!!!

I do truly appreciate this forum and all the members that give feedback for the betterment of myself and others alike. I have also included some pix of the O2sim light on and the error code. thanks again!!!
 

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Don't forget to clear the error codes using a OBDII code reader to turn the check engine light off and see if the problem persists.
 

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Oooooh oooooh oooooooh, I got a quick fix... when you find those two wires (and, yes, this is serious) just cut up any extra wires you have in your garage (if you're like me and have extra wires everywhere) and just stuff it in each pin socket... it still transfers the same amount of energy (I honestly didn't think it would but it did). I did this the day before I got my smog check and i actually STILL have it in the way I described... don't cut your wires ,especially if it's gonna be temporary.
Now will doing this short anything ?
 

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Hello from Germany =) I m proud owner of a Lexus IS 300 model 2002 and my main Forum is Lexus Owners Europe. I install the Megan header + Megan downpipe and O2 Simulator but i still have 2 errors (p0161 and p0141).
I tried to find some solutions on different forums but nobody can help me.
So this forum is my last chance. Can anybody show me a wiring plan of a 2002 IS300 for the heater signals? Or any idea how can I fix a the 2 errors?
I enjoy reading your posts and I m happy, that there a lot of helpful people on this Forum.

Thank you

David
 
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