O2 sensors?

[dobbslc]

The boys Toyota Aygo has just thrown a code for the pre CAT OW sensor, we've tested it quickly and it seems ok and cleared the fault but I suspect it will happen again. What are the best alternative makes to buy with O2 sensors? Toyota want about £160!

 

[premmington]

The boys Toyota Aygo has just thrown a code for the pre CAT OW sensor, we've tested it quickly and it seems ok and cleared the fault but I suspect it will happen again. What are the best alternative makes to buy with O2 sensors? Toyota want about £160!

Some after market O2 sensors while they work - they are slow (lazy) to switch - which will give cat aging errorcodes in use.

Some vehicles will be OK with lazy sensors and the software will be OK with it - others are more sensitive and will flag the EML on.

I have fitted countless NGK O2 sensors with very few problems.

I would thou always prefer to fit a main dealer O2 sensor if the budget will allow.

 

[dobbslc]

I've read that the Toyota's can be fussy.

 

[premmington]

I've read that the Toyota's can be fussy.

Yeah it has always been cars from Japan - Honda and Toyota's that have been fussy.

But your Aygo - has a bit of Citroen C1 Peugeot 107/108 in it - made in Czech'

I reckon you would be ok with a good named pattern one.


Aygo/C1/107 not a bad little car - not seen too many problems with them in my workshop - don' think I have ever put a pre cat O2 sensor into one.

 

[dobbslc]

It's been a good car! It needed a second hand power steering ECU which seems to be common and the passenger seatbelt pre tensioner had a dodgy connection due to the seat being rammed back and forth all the time (its a 3door)
I've found a Bosch pre cat sensor at GSF for about £80 but we'll see what happens after clearing the fault...
Just to be sure it said bank 1, is that pre or post cat?

 

[premmington]

It's been a good car! It needed a second hand power steering ECU which seems to be common and the passenger seatbelt pre tensioner had a dodgy connection due to the seat being rammed back and forth all the time (its a 3door)
I've found a Bosch pre cat sensor at GSF for about £80 but we'll see what happens after clearing the fault...
Just to be sure it said bank 1, is that pre or post cat?

Bank 1 is for a 4 or 6 cyl engine with one cat.

Only V6 V8 V12 engines have bank 1 and bank 2.

 

[dobbslc]

Mmm interesting. I'm sure it's only a little triple under the bonnet
So bank 1 will be right but which sensor?
I'll plug the code reader back in and check before buying anything.

 

[qwakers]

Bank 1 sensor 1 is pre cat, bank 1 sensor 2 is post cat. Exactly what code is it? There are 3 or 4 different codes it could throw and not all of them are caused by the sensor.

 

[premmington]

Bank 1 sensor 1 is pre cat, bank 1 sensor 2 is post cat. Exactly what code is it? There are 3 or 4 different codes it could throw and not all of them are caused by the sensor.

 

[dobbslc]

P0420 bank 1 is what I remember, I can't remember what sensor it said . So if I'm thinking correctly we only have one bank?
We did a few checks like the heater wires and got 11 ohms and 0.75v at the unplugged wiring loom socket.
Now I know what to look at I can get live data off my scanner to see what's happening.
If the fault returns...

 

[premmington]

P0420 bank 1 is what I remember, I can't remember what sensor it said . So if I'm thinking correctly we only have one bank?
We did a few checks like the heater wires and got 11 ohms and 0.75v at the unplugged wiring loom socket.
Now I know what to look at I can get live data off my scanner to see what's happening.
If the fault returns...

P0420 - You in for live data and swtiching times for the O2 sensor.

Might be the CAT is on the way out - you not had misfiring or oil usage of late - flooding the CAT with hydrocarbons?

 

[dobbslc]

Might be the CAT is on the way out - you not had misfiring or oil usage of late - flooding the CAT with hydrocarbons?

This is the same car that the boy run out of oil about 3 months ago, engine light on and "a noise". He'd run it out again a couple of weeks ago.
It's using oil no doubt about it...
The dip stick on these engines is a very shiny piece of stainless steel and even I have trouble telling where the true level is as it smears the oil up about 3" one one side so if you look at that it looks over filled
The Surf is the same.

 

[qwakers]

That is a bank one sensor two catalyst efficiency code if it is burning oil then you have a poisoned cat almost certainly.

 

[dobbslc]

It's definitely using oil but it's not as bad as an Audi for instance.
So you're saying it's the post cat sensor?
I may try some cat cleaner in it and see what happens.

 

[qwakers]

If that is the correct code and my code ref is correct, yes.

 

[Ruffian]

Jap stuff has been bad for lambda sensors,

Fit either a decent brand or genuine only. And from a reputable source!

Subaru, toyota and honda have all been really fussy.

Would certainly make sure the manifold isn't cracked either as the aygo/107/c1 range are known for it.

 

[dobbslc]

The O2 light came back on last week with the same code I think but the boy cleared it before I had a look
It's been ok since...

Airbag light is back on now and after hitting a massive pothole two weeks ago and shredding a wheel and tyre he's hit a curb earlier this morning and shredded another wheel and a brand new tyre.
**Language**ing AA left him stranded even though we got him the full cover for recovery etc.
Luckily his girlfriend has a Citroen C1 and took her spare wheel to him and he's got home at about 6am.
AA will be getting the full Monty off the missus some time today demanding a full refund.
Tossers.
Anyone got a pair of steel 14" Aygo rims for sale?

 

[dobbslc]

I had a look at the live data on the O2 sensors today, here's a photo of the graph.
On the left side the engine is idling and on the right it's at about 2000 rpm.
The blue line is sensor 1 pre cat and the black line is sensor 2 post cat.
From what I've found online at 2000 rpm the pre cat sensor should pulse up and down like it shows but the post cat sensor should run almost straight which it's not!
Does this point towards a knackered cat?
Thank for any help

 

[m_c]

That would point towards a catalyst that's not doing what it's supposed to, which given my limited experience of petrol Toyotas, isn't that uncommon.

 

[Keithmac]

I would expect post cat to be flat lined as you say. Looks like there's no cat in it if that is the post catalyst sensor..