O2 Sensor Removal

[Andy C]

Hi Guys,

I have been getting an intermittent fault code 13 .. so I guess after 20 odd years, I need to replace my O2 sensor .. except the f*@&ing thing just wont come out!

I have sprayed/soaked with WD-40 for a week ... that didn't work

Went for a drive (emitting clouds of burning WD-40 smoke) to get everything really hot ... that didn't work either.

I have the correct size open end spanner ... that just slips under load due to the fact that I can't get it on square because of the turbo heat shield

I have a O2 sensor removal socket .. that doesn't work either, it just seem to expand a bit when under load and slips.

So far all I have managed to do is start to round off the flats on the flange.

So ... seems my next step is to butcher the existing sensor and snap off the top so I can get a proper socket onto it with a long bar and force the bloody thing off ..

My question is ... if I do this (destroy the existing) and I still can't get the thing off ... will the car still run? .. just incase I have to end up taking it to my local mechanic to get it removed, I don't want to have to get it there on a flat top

Or .. does someone have an alternate way of removing the stubborn thing

Thanks

[Fetnas]

Not that I've tried this, but I believe getting the exhaust hot then placing an iceblock on the sensor can cause enough thermal shrinkage to break the resistance. My car is an early s1 and doesn't have an O2 sensor, but I do intend to upgrade and will have this problem when removing the existing bung.

Good luck.

[HJ2]

I usually use an O2 socket as well, but put a LARGE grip pliers on it when it's on the sensor, to prevent the socket from flexing.
I hope that helps!

[Simon_P]

I have just done this, and you think it will never come off and the people who sell sockets with splits in should be held accountable.

With the socket on square and my Britool torque wrench wound up to whatever the socket would take without splaying out (about 110 lb ft) I kept trying. The Britool torque wrench has a really strong click action and in frustration I clicked it past the action about 20 times while keeping the load on, like an impact gun I thought...and off it came?

[HJ2]

So 02 socket, grip pliers, lubricant AND brute force should do the trick! (I Use an extendable1/2" ratch for this)
http://www.ebay.com/itm/1-2-Extendable- ... 1140629716

[lotusflasherman]

I use a short length of steel tube as a sleeve to stop the split socket spreading. (Don't know why manufacturer hasn't made it part of the socket.) Put that on a 24" breaker bar and always found they undo without much protest, or lubricant, when 'stone cold'...(unless secondary sensor on an exhaust pipe where shearing the boss off the pipe has to be considered with that much leverage but that's not a problem on the Elan).

WD-40 has it's uses but is a waste of time on most things where 'proper penetrating oi'l is required. Very difficult to get anything to go down the threads of an O2 sensor so BIG TORQUE is best.

[HJ2]

Steel tube sleeve! .... Top tip!

[lotusflasherman]

Not that I've tried this, but I believe getting the exhaust hot then placing an iceblock on the sensor can cause enough thermal shrinkage to break the resistance. My car is an early s1 and doesn't have an O2 sensor, but I do intend to upgrade and will have this problem when removing the existing bung.

Good luck.

Iceblock doesn't take much heat away and you get water everywhere... a blast from a CO2 fire extinguisher is much more effective but watch out for 'freeze burns'..

[Andy C]

Thanks guys,

I tried the vice grip option .. and the sleeve option .. and all I managed to do was round stuff off more! .. this is really starting to give me the shirts

I suppose I can answer my own question by just unplugging it and trying to run the car .. if it works, I might just snap off the top and get a real socket on the damn thing

[muley]

I placed a Jubilee clip round my socket to stop it splaying. The socket was created by carving a slit in the top to let the wire go through. Used Plus Gas and a LONG lever and out she popped.

Jim

[GeoffSmith]

I ended up using penetrating oil, lots of heat, Stilsons/pipe wrench and a scaffolding pole.

[Artaban]

I ended up using penetrating oil, lots of heat, Stilsons/pipe wrench and a scaffolding pole.

Funny, exactly what I used to use to get my teenage son out of bed in the morning

[GeoffSmith]

I ended up using penetrating oil, lots of heat, Stilsons/pipe wrench and a scaffolding pole.

Funny, exactly what I used to use to get my teenage son out of bed in the morning

Just wait until he gets into his twenties... That's when it gets really hard!

[lotusflasherman]

Thanks guys,

I tried the vice grip option .. and the sleeve option .. and all I managed to do was round stuff off more! .. this is really starting to give me the shirts

I suppose I can answer my own question by just unplugging it and trying to run the car .. if it works, I might just snap off the top and get a real socket on the damn thing

What socket are you using and what sleeve did you use ?

I've got a 3/8" drive socket (on the left) which is OK for fitting O2 sensors but 'king useless for removing them. The 1/2" drive socket (on the right) with a tight fitting sleeve over it (cut from the tapered tube of a garden fork on it's way to the dump) is as solid as any deep socket I've got but if the sensor is being replaced I usually cut the wire off to get it out the way. Bought those for checking the sensors on my daughter-in-law's Renault Clio - the primary sensor is down the back of the engine and about as accessible as the Elan's alternator!
Glad to say I've got an SE on Open Loop so they are not something I have to worry about, though I fitted a sensor to drive a fuel mixture LED display but disconnected it as found it distracting at night. (One day I'll add a switch ... )

[Kathryn]

Sounds exactly like my experience of the O2 sensor removal. I gave up quickly and asked my brother to do it. The removal tool was useless as were various spanners, my brother was very frustrated he couldn't do it -and he dented my turbo heat shield too! I ended up taking it to a garage where the mechanic changed it for a tenner cash in hand!

[Andy C]

Okie dokie,

I finally removed and replaced this damn thing, and in the end it was easy!

To answer my original question ... with the O2 sensor disconnected, the car runs fine, although you do get a CEL. So, once I was armed with this knowledge I took the plunge and snapped off the top "pointy bit" of the sensor so I could get a normal socket onto the nut portion. It snapped off easily with a few hits of a medium sized hammer .. most of this section is ceramic. I made up a mix of 50% acetone + 50% auto transmission fluid ( a tip from my BIL) .. after soaking in this for about 20 mins, and with a normal 22mm socket on a breaker bar, the remains of the sensor came out easily. You could see where the 50/50 mix had penetrated down the first couple of lines of thread .. apparently this mix is the "best penetrating fluid available".

So .. after removing the heat shields for a quick polish, and installing the new 02 sensor, this job is done Just don't get me started on the stupid bolt placement to remove and replace the turbo heat shield

[CalElan]

You call the bolt placement stupid, but given the number of fastenings on the Elan that are nigh-on impossible to see/ reach/ get a tool onto/ undo at more than 8th turn a time, I have to suspect there was a committee of malevolent engineers specifically tasked with making our lives as difficult as possible.

Glad you got it sorted!

[tedtaylor]

having same issues (CEL, code 13, O2 sensor), however i cannot remove it either.
My question in this is, can the O2 sensor be cleaned and reused? or are they impossible to fix and thus a replacement only?
Please advise as my first thought was to remove it to thoroughly clean it, reinstall, and see if that fixes it.

BACKGROUND:
I was on a 200 mile cruise today, started with full tank of gas with Techcron mixed in to clean my injectors (routine maintenance, no problems present)
Ran down below 1/4 tank (low fuel light did NOT come on yet), pulled into gas station and filled up (11 gallons) with middle grade "plus" gas. Shortly after the fill up with only a mile or two down the road, the CEL came on!!! I pulled over thinking i filled tank too high, overflow into evap system, or something screwy with gas cap. I removed cap, re-fastened gas cap again, restarted engine....CEL was out, but only another mile or so and BINGO, it came back on. Car is running perfectly fine. Got home to check codes and found the "13" 02 sensor code.

[Brit-Car-Nut]

O2 sensors CAN NOT be cleaned. If you even touch them, they will go bad and any kind of spray kills them immediately.

I have tried several times to remove the original one in my car and it is frozen. Since it hasn't run more than a few minutes since I got it in 2008, I figured I would wait until other projects are sorted and then drive it for a long trip and try again.

I have spread or otherwise damaged 4 different O2 sockets from Snap-On and MAC and several from anywhere I could find something that looked to be "stronger". My friend (BMW/Mercedes shop owner) even came over with a socket/wrench he said never failed and he destroyed it as well. It hasn't been an issue, so I will get it sorted before I actually drive it regularly.

[tedtaylor]

OK, so shoot me now for being so cheap!!! (asking about cleaning them)
I went online and ordered one from RockAuto that is depicted for the '91 Isuzu Impulse turbo. I don't know why they aren't cross referenced and listed under their Lotus Elan M100 section!!!
There were several to choose from, so I opted for the Bosch 15701 with 15" lead for $36.00 THe other Bosch unit as cross referenced under the Golden Gate Lotus Club parts directory was over $55 bucks with a 12" lead, so i see no other difference. There was a Delco knock off and two others as well. It is being shipped and should be a direct replacement.

Before replacement, I reset the ECU by disconnecting the battery, waiting 30 seconds, and reconnected. I test drove the car with no CEL until 15 minutes into the trip when the temperature got up to normal, and sure enough....BINGO, the CEL came on again. So much for luck!

Since i order the new part, i opted to cut the leads. The unit is still too tall to fit a 22mm socket overtop, so i got a big slip-lock pliers and pried the neck off, breaking up the ceramic insulator and removing the brass body. I was then able to easily put the 22mm socket over and with a breaker bar, typical normal effort to remove. it came right off.

I'll update when the new one is installed and after my test drive. Wish me luck!!!