PO141 o2 sensor heater resistor

[roguk]

Hi took my car out for a spin first time for months and the engine management light came on.
Error code PO141 O2 sensor heater circuit bank 1 sensor 2, lots of posts on here about it and resistor mod, but no info on resistor size or wattage (originally it was 15 ohm 15 watt) but that i believe is now not correct, any one know what it should be please ?

[StuC]

LINKY

These are the ones I supplied to Ding Day a few years back. They are still available.

[roguk]

Hi Stuc thanks for quick reply and link, will wait for when they are back in stock.

[StuC]

This looks to be a suitable alternative. I wonder if this is it's successor.
Specs seem to match looking through the data sheet. Have a peek for yourself though.

[roguk]

Thanks Stuc same spec resistor so have ordered, will let you know when fitted.

[StuC]

No probs.

If it works, let me know.  s:-D :-D s:-D

If you car blows up, less so.  s;-) ;-) s;-)

Seriously though, it should be fine.  :-) :-) :-)

[lamcote]

This one is also reported as working on YouTube -

 m https://uk.rs-online.com/mobile/p/panel ... s/0160736/ m

Not sure whether the lower wattage will be a benefit or not?

[StuC]

I was lead to believe that the wattage was important, that's why I tried to find a 50w.
I am a simple mechanical engineer. I don't understand this electrickery stuff.

[lamcote]

I have just watched a YouTube video by (I assume) leethesparky and he says he used the 25w version I posted the link to. Just thought I would mention it as a seemingly tried and tested option, I have absolutely no clue about the whys and wherefors of this myself.

 m https://www.youtube.com/watch?v=H6mX4efePx8 m

Maybe someone with the appropriate knowledge can chime in if necessary?

[roguk]

Thanks for replies guys, resistor arrived this afternoon will fit tomorrow and report back.

[StuC]

As far as I can tell the Wattage relates to the heater element side of things only.

[shnazzle]

The wattage relates to the voltage on the system and the resistance.
So it's easy to calculate the required wattage once you know the resistance provided by the heater element on a working sensor and the voltage across it

[lamcote]

.... and the answer is.... ??

[shnazzle]

Dunno. Too lazy to go out and check hahaha. Sorry, being totally unhelpful. I'll happily do it tomorrow though

[lamcote]

Bit of research suggests that the resistance varies with engine temperature, if I've understood it correctly, but it is all totally confusing to me, I've never grasped electronics.

I get the impression that the higher wattage ones (ie StuC's suggestion) might be best, but I'm really not sure why.   s:scared: :scared: s:scared:

[StuC]

If you are using Ohms law to determine a particular reading back at the ecu. Then surely using a low wattage, with the same resistor would give you a different reading? or is that too simple?  s:lol: :lol: s:lol:

I think I am correct in saying that you can only use the "resistor fix" for the rear sensor,  i.e. Bank 1 Sensor 2.

[lamcote]

From what I have seen lots of people have used it on all three sensors.

[ChrisGB]

I used 34 ohm 20w (well 2 x 68 ohm 10w in parallel). No problems with that. The lower the resistance, the more current you draw from the 12v source.

[lamcote]

So we have:

15 Ohm 25W
27 Ohm 50W
34 Ohm 20W

All working OK, can you just use anything or is there a theoretically correct spec?

[shnazzle]

At 12v and 34ohm science tells me it should be about 4w. Take that liberally and 8 should do the trick. 20 certain covers all bases  s:) s:)  Or the actual resistance is more like 15ohm.....

[roguk]

Hi, all done fitted resistor (27 ohm 50 watt £2 89p inc free next day delivery) behind left rear light unit, took about 30 mins, cleared code and went for a spin.

[Bossworld]

Hi, all done fitted resistor (27 ohm 50 watt £2 89p inc free next day delivery) behind left rear light unit, took about 30 mins, cleared code and went for a spin.

Did the code stay off?  I'm guessing this won't fix the P0136 for the same sensor?

[StuC]

Nice and neat. I guess if it's gonna fail it'll be in the first month or so of usage.

Keep us posted.  :-) :-) :-)

[roguk]

Will do and Thanks for help.