PO 0141 Post Cat Sensor

[normanh]

Just had this fail yesterday, ordered a replacement from Sparkplugs got it today at a very good price for Denso DOX 0206. Question - I dont have a sensor socket but I do have a deep 22mm ring spanner - has any one else used one of these to take out the sensor, it looks possible, just as I went to get under the car the skys went black and the rain dropped? End of attempt! Next question where does it plug in - looks like the plug on the left side of the coolant bottle, if so how many clips hold it in place, looks like one on the underside but I cant see any more due to a crap right eye - cataract? Cant see close up just about on distances.

Norman

[Carolyn]

If you have the original cat with its heatshields, you'll find it's very difficult (impossible) to get the ring spanner in the space.  I have aftermarket manifold and cat, and I use a ring spanner as the tool of choice.

One way to deal with it is to cut the protruding metal off the sensor and use a six-point socket on the remains (usually with a breaker bar).  Sounds radical, I know, but you are ditching the sensor.

If you remove the Near-Side tail light (two screws and a bit of fiddling), all should become clear when it comes to disconnection. 

[normanh]

I've got a deep offset ring not a combi spanner. Good thinking on the rear light thanks.

Norman

[paulj]

I was going to offer to post you my O2 sensor as it has only been used once....but it looks like cheap new ones are £8-11 and I would guess the post there and back would cost us the same!

It will need a bit of welly so heed the breaker bar advice.

[normanh]

Hi Paul thanks for the comments.

I have the sensor socket picked it up from my mechanic brother. I have changed the others in the past never needed a breaker bar but I'll give it a squirt of penetrating oil and let it soak before I attempt its removal.

Norman

[Gaz mr-s]

Dick Sloan has told me that sometimes it can destroy the cat trying to remove it.  A garage that's worked on mine has said similar about other makes.

[normanh]

Its seized solid, gave it a second soak in penetrating oil, even put a hose clip on the end of the socket just wont budge. Have ordered a socket with a smaller wire slot - just 8mm to see if that will help as I couldnt hold the breaker bar square to the sensor on handed as its risky to use my left hand since I chopped off the top of my index finger last year its still very painful if caught.

Not sure what to do now but toying with the idea of replacing the cat as it only just passed emissions in January but replacing that could be a struggle with the 3 amigos for the same reason my left hand.

Norman

[Gaz mr-s]

The fault with mine was just the heater cct, so I just fitted a resistor to deal with it just now.  The garage's next step would have been heat.

[Joesson]

Its seized solid, gave it a second soak in penetrating oil, even put a hose clip on the end of the socket just wont budge. Have ordered a socket with a smaller wire slot - just 8mm to see if that will help as I couldnt hold the breaker bar square to the sensor on handed as its risky to use my left hand since I chopped off the top of my index finger last year its still very painful if caught.

Not sure what to do now but toying with the idea of replacing the cat as it only just passed emissions in January but replacing that could be a struggle with the 3 amigos for the same reason my left hand.

Norman

If I remember correctly @Carolyn suggested that you remove the top of the sensor to allow the use of a ring spanner, that would avoid the opening up of the split socket that is likely causing the problem.
Then you could use a regular 6 point socket and a breaker bar.
If your car is all OE access to the socket is likely the root cause of the removal problem.
I removed that sensor without removing the bumper but if you were to do that access would be easier.
PS I may have elevated the rear on axle stands to help access, and plenty of penetrating fluid.

[Carolyn]

Its seized solid, gave it a second soak in penetrating oil, even put a hose clip on the end of the socket just wont budge. Have ordered a socket with a smaller wire slot - just 8mm to see if that will help as I couldnt hold the breaker bar square to the sensor on handed as its risky to use my left hand since I chopped off the top of my index finger last year its still very painful if caught.

Not sure what to do now but toying with the idea of replacing the cat as it only just passed emissions in January but replacing that could be a struggle with the 3 amigos for the same reason my left hand.

Norman

If I remember correctly @Carolyn suggested that you remove the top of the sensor to allow the use of a ring spanner, that would avoid the opening up of the split socket that is likely causing the problem.
Then you could use a regular 6 point socket and a breaker bar.
If your car is all OE access to the socket is likely the root cause of the removal problem.
I removed that sensor without removing the bumper but if you were to do that access would be easier.
PS I may have elevated the rear on axle stands to help access, and plenty of penetrating fluid.

I know you didn't want to believe it would be such  piglet - but it's pretty normal, I'm afraid.

Get the car as high as you can, follow the advice, use a plumber's torch to get some heat in it - and you will prevail!!

[potge]

Before changing the sensor have you actually checked with any diagnostic tool the sensor`s behavior?

Most probably is the sensor, but it does not harm to check.

[McMr2]

Probably not the answer you want, but I resorted to taking the cat pipe off and getting it onto a bench when mine needed replacing.

Wrecked the old sensor in the process but a long socket with the cutout did the business.

[normanh]

Next attempt will be heat - either a small propane torch as Caroline suggests of a heavyweight oxy torch, likely will take the bumper off to prevent damage.

Todays out its hissing down.

Norman

[Joesson]

Next attempt will be heat - either a small propane torch as Caroline suggests of a heavyweight oxy torch, likely will take the bumper off to prevent damage.

Todays out its hissing down.

Norman

I'm still of the opinion that access is your problem, with the car elevated you would get better access. With the bumper off you will get better access. Meanwhile I would still be applying the penetrating fluid such as PlusGas. (Not WD40)

[paulj]

I agree with a bit of elevation. Having a clearer area for more purchase worked on mine.....that and a breaker bar.

[normanh]

Guys

I have had the car up pretty high on a jack, its been soaked twice in a good penetrating oil from my local motor factors, I have tried both 3/8 and 1/2 drives with a 2 foot breaker bar. Access hasnt been a problem but I trying to do the job one handed as I cant risk damaging my left hand index finger. Taking the bumper and rear light cluster will give a much better access with the car off the ground I know I just need to get someone to help - hold the socket firm as well as break the seal with a new socket I have splayed out the one I have borrowed the sensor is dam tight. The bumper is coming off if I have to use oxy rather than a small butane torch.

Like I said I am tying this one handed!

Norman

[Carolyn]

Guys

I have had the car up pretty high on a jack, its been soaked twice in a good penetrating oil from my local motor factors, I have tried both 3/8 and 1/2 drives with a 2 foot breaker bar. Access hasnt been a problem but I trying to do the job one handed as I cant risk damaging my left hand index finger. Taking the bumper and rear light cluster will give a much better access with the car off the ground I know I just need to get someone to help - hold the socket firm as well as break the seal with a new socket I have splayed out the one I have borrowed the sensor is dam tight. The bumper is coming off if I have to use oxy rather than a small butane torch.

Like I said I am tying this one handed!

Norman

Yes - you need a bit of help, I think.

[krazysteve]

Next attempt will be heat - either a small propane torch as Caroline suggests of a heavyweight oxy torch, likely will take the bumper off to prevent damage.

Todays out its hissing down.

Norman

Mapp Gas is better puts more heat out, try dabbing with wax candle, also if stubborn, heat and cool quick with a spray bottle of water a few times. thermal shock. 

nb if all fails sell the cat fetching circ £150 and buy a new euro cat cheaper lol. X05 is the cat code   x06 import only fetch 65 ish 

[Ardent]

@normanh

Where are you based?
I would be happy to lend some muscle if close enough.

[normanh]

Thanks for that offer Ardent, hopefully I can have another go next weekend with the new socket. PM sent

Norman

[paulj]

Happy to help too - but if you are close to Ardent it will be quite a hike from Devon!

[1979scotte]

Norman is an Essex boy

[normanh]

Latest - its fixed , its had several heat cycles and a water drenching followed by penetrating oil. My son simply cut the wire off and a quarter of a turn with a deep 22mm socket he unscrewed it with his fingers. Reset the code all done.

Norman

[normanh]

Last update - the Sensor was fixed on its replacement but on my ELM257 a cat failure still showed and was persistent for months. Just checked it today and all issues have been cleared so a new cat is not needed for now.

Norman