ok so i'm trying to get my car in my sig to pass inspection, i already got a new cat and o2 sensors (NTK, which are probably the wrong ones) but my question is, the CEL comes on within 3 seconds of clearing it, with code P0141 secondary o2 sensor heater circuit. I've heard of using spark non-foulers (which i got already) for the rear. normally i would just go out and put them in myself but i'm away at school and want to know if its worth waiting to see if that works or should i order the (correct) rear o2 sensor, which would beee..... Denso 234-4621($50), or should i just get the Honda one from majestic for $100. If i end up getting one more freaking o2 sensor that doesn't work... uwigbaiwbgahhhh
thanks for the help

 

anybody?
will the non-fouler clear the heater failure code?

 

No a defowler should not fix that code. A defowler hides the HO2S from dirty emissions from a bad or missing cat. The heater circuit code was not triggered due to the exhaust.

Check Fuse 6 in the Driver's under-dash fuse/relay box.

Unplug the secondary HO2S, leave it installed in the exhaust:

• measure the resistance between terminals 3 and 4 of the sensor. Is there 10-40 ohms? If not replace it.
• check for continuity between 3 and ground. If there is continuity replace the sensor.
• check for continuity between 4 and ground. If there is continuity replace the sensor.

If all tests for the sensor are good continue:
Start the engine:
measure the voltage between pin 4 at ground, is there battery voltage? If not repair open in the wire between the No. 6 ECU (ECM/PCM) CRUISE CONTROL (15A) fuse and the HO2S.

There are a few more steps in the directions, but let us know where you are after checking these.

 

thanks a lot ControlNode, this is exactly what i was looking for. hopefully i'll get a chance to go home next weekend and do these tests, the car should probably be warmed up since then it would go into open loop right?

 

No need to warm it up. Most of the tests are on the sensor with it disconnected anyway. Only test that is not to the sensor on its own was the voltage test while the engine is running, and warmed up or not that voltage should be there.

 

im gonna be doing the test tomorrow morning, i'll post back with the results!

 

ok so here's what i found..
tested the secondary o2 sensor from T3 --- T4 read ~3.6Ω. based upon this, the sensor should be replaced, but i went ahead and did everything else anyway
from 3 or 4 on the sensor to ground there was no continuity. (which is good)
with the engine on, i tested all the pins to ground and none of them read above 50mV. i'm not sure why it's giving such a low reading, but that's what i got.

on my brother's 98 dodge truck he was driving around without the rear o2 sensor in for a while and there wasn't any code showing up, so i decided to give that a try. i removed the sensor and saw that it was almost all the way covered in black, but had condensation on it too. is this normal?

so i have that dangling, reset the ecu, start it up and the CEL comes back on within 3 seconds.
next step: what if it wasn't plugged in at all? reset ecu --> CEL again.
after that: reset ecu, plug back in and put back in exhaust with the defowler setup, code comes back again.
after doing that i decided to check the front o2 sensor and from pin3-4 it was showing 1.8Ω, which is even lower than the rear but i don't think its throwing a code...

now everything's back to how it was when i started, but i was wondering what's the deal with it being black and having condensation? it might be useful to add that i have a 4-2-1 header so the primary sensor is only in about half of it (idk if that even matters, because it's measuring the Ratio, not amount) and a magnaflow catalytic convertor, which has the hole for the sensor about halfway through it.

also, when i put in the new sensor should i use the defowler over it just in case its still running rich? i reeeally don't want to ruin a brand new $140 sensor.

thanks a lot for any help/tips to get me to pass inspection

 

btw the front o2 sensor reads:

DU2
DENSO
192400-1020
09825
Japan

102

 

one more thing:
the new front o2 sensor that i got but ended up taking out because i think it was throwing a code (i forget if it was or not) just tested 15 ohms from pin3--pin4 and is not nearly as black, just a little around the base
it's a NTK 24655
on the sensor itself:
ASSEMBLED
IN USA
5360
05K14

 

when it comes to o2 sensors i would recommend to keep it oem denso ... you just have to make sure you get the right one ... that 234-4621 denso is $35 @ http://www.densoproducts.com/ ... but wherever you get it from make sure it's for your f23a4 ...

http://www.densoproducts.com/results...ctCategoryID=2

 

nice i guess it went down a couple bucks
thats the one i would much rather get and save $100 i just wanted to know if anyone used it before and had it work or not work i'll wait a couple days and see if anyone posts

 

just to be 100% sure ... which sensor are you looking to replace both or just the one on the cat? ... that way i can look at my f23a4 and see what sensor is on it ... i recently replaced the primary o2 [the one on the exhaust manifold] ... it cost me $200 from denso ... unfortunately it was my cat that was bad not the sensor ... FAIL lol

 

thanks for offering to go look it up but i'm almost positive the 2001 is different than the 2000 (for the primary anyway). i have a big list of denso part numbers that cross reference to something but i'm not sure what parts, and i saw another post about it on here before, damn hondas are so picky!!! anyway, i'm looking to replace the rear first because even if the front one is throwing a code, it's not the one thats going on right away, so i'll start from there lol
and nice job haha

 

and it's the cheaper one lol ... i would definitely start there when playing the guessing game

 

anybody have success/failure with the Denso 234-4621 on a 2000 EX?

 

forgot to post back, but if anyone searches for this it worked. Denso 234-4621 with non-foulers and the code has stayed away

 

Hi, I have a Honda Stream Year 2001, the Oxygen sensor malfuntion need to replace. Does anyone know where to get the part of Denso DU2 192400-1042? Or any parts can replace it? please advise