O2 Lambda Sensors - Please help

[Zippee2020]

Hi Guys Im new to the club but  have owned my mint 51 plate roadster for 3 glorious trouble free years.......until now

Took it for the MOT and it failed on emissions, turned out the cat was kaput so got this changed

Took the car back for retest and found that the garage that fitted the cat had not fitted a new gasket so it failed again!!!!

Got gasket fitted and at the same time upgraded the manifold to an aftermarket decat manifold to overcome issues with the precat I have read about on these forums (thanks for the heads up)

Anyway, car passed MOT and on return home the engine light came on, plugged in diagnostics reader and it came back with error codes P0141 AND P0155

I cant help but wonder whether the sensors were damaged when the exhaust was changed

However I have also read that the removal of the precat in the manifold can also cause problems with the sensors

Please help,do I replace sensors (if so which ones need changing as I look at engine), clean sensors (which somebody has suggested) or I have also read about fitting spacers - whatever these are ?

Would welcome any urgent advice as I hate running my car with the engine light on

Also if i need to replace, will go with Denso ones but which part codes do I need?

REALLY APPRECIATE ANY HELP OUT THERE THAT SOME ONE CAN GIVE ME   s:crazyeyes: :crazyeyes: s:crazyeyes:  

Many thanks

Mark

[StuC]

P0141 is bank 1 sensor 2. Which is the one after the main cat near the bumper.

P0155 is bank 2 sensor 1. Which is the one on the left hand side of the down pipe.

Both are heater circuit malfunctions, which you can fix one of 2 ways. Either with an inline resistor or replacing the sensor.
You can get the resistors from RS.

If you chose the other route make sure you get a Denso replacement not a cheapy part. They have a habit if failing... often!

Edit: trying to find the links on my phone. So bear with.

[StuC]

Link to Sparkplugs.co.uk for the replacement sensors.

Linky

[AmeR]

Don't use the resistor fix across the manifold sensors as they are used for fuelling.

They are quite sensitive, especially after going through a few heat cycles so can become damaged during removal / replacement.

[Zippee2020]

Many thanks for the replies guys, how about part numbers I can't see any on my fitted sensors,:(

I checked eBay and a trade seller is listing the post cat sensor as DOX0109 which at the spark plugs site is a mere 36 inc vat!!!

I think the pre cat is DOX0206 which is more at 60 inc vat

(I don't want to splice wires together just a straight swap)

I have emailed spark plugs and they said contact the dealers, knowing dealers as I do, I don't think they will be very informative when they realise I don't Intend buying the part off them! LOL  s:) s:)

Thanks again, I'm really impressed with the club and the community spirit, will check out the events and hope to attend some as soon as summer finally gets here!

[StuC]

Front (manifold) sensor is DOX-0204

Rear (post cat) sensor is DOX-0206

It's all on the link I posted, if you input the vehicle type.  :-) :-) :-)
Were you doing in on your phone by any chance?

[Zippee2020]

Yes I was, Apple's got a lot to answer for! Many thanks for your advice and reply again

Mark

[StuC]

No worries. I am sure I struggled doing it on my phone too!  s:lol: :lol: s:lol:

[Zippee2020]

Ok denso sensors arrived - next day delivery - really impressed !

I'm struggling to free the left sensor from its coupling and don't want to force it!!

The coupling is inverted and mounted on a metal bracket and no matter how hard I tug on it I can get the socket to part

Can you come to my aid again with some advice??

Many thanks!

[AndyM]

Got recently frustrated with this myself. There is a pressure catch on the underside of the clip (check out the top of the right hand side one for comparison). They can be quite stiff.

In the end I found getting a bit more height (standing on a toolbox) meant I could get a better angle to squeeze a hand down the side to press the catch while the other pulled the plug from the front.

[Zippee2020]

Cheers Andy ill give it a go and report back!

[Zippee2020]

Ok coupling free but sensor wont budge, I've sprayed with wd40 and ran engine for a couple of minutes to warm exhaust

I bought a 22mm sensor socket but it won't move I'm worried if if put too much torque on it it will shear off!! Any ideas

Also sensors instructions talk a out 20 Newton metres pressure -I don't have a torque wrench how critical is correct torqu on sensor?

[AndyM]

Again, I had the same issue with the sensor too. I gave it an ample serving of Plus Gas and let it soak in, then another splash before warming up the engine. Once it was warm it was just a case of giving it some beans but it eventually budged.

[Zippee2020]

Sensor update ! Top one done and have renewed sparks and air filter, engine seems to be more lively!

Next is one at bottom and oil and filter change!

[StuC]

Great job on getting that top one sorted  :-) :-) :-)

[Zippee2020]

Bottom sensor changed (had to remove rear light cluster to unplug and plug back in new sensor, oil and filter changed and wax oiled cross member which was showing some signs of corrosion, overall though car really sound underneath, toyota do really care about quality!

Also bolted on engine cover better than a decade of mechanics ever did, which included them  using plastic ties to replace the bolts they had lost over the years!

Cleared the engine warning light and the 2 is driving like a dream!

Many thanks to all those who helped me, this club and its forums Are a god send for any respecting Roadster owner!

[AndyM]

Good job  s:) s:)