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Pre-Cat O2 sensor

Posted: Sun Mar 14, 2010 6:02 am
by stux99
Help! Is changing this a DIY job?
Also, huge price differences when searching, best value place to buy?

Stu

Re: Pre-Cat O2 sensor

Posted: Sun Mar 14, 2010 8:00 am
by Steve White
I purchased one recently on ebay from MGManialtd (Glen Sprigg), which was the genuine MG part. £35 + postage
Changing them can be a pain. It all depends how easily the old one can be removed. I can be easier to remove that section of exhaust and remove the old sensor once the exhuast is off the car.
Personally I would get a garage to do it, but then I'm lucky enough to have Techspeed on my doorstep.

http://cgi.ebay.co.uk/MGZR-MGZS-MG-ZR-M ... 45f0f63ff5

Re: Pre-Cat O2 sensor

Posted: Sun Mar 14, 2010 8:19 am
by Geoff.F
A common problem is tearing of the female thread in the exhaust. Do not buy a new exhaust but get an engine shop to fit a spark plug helicoil insert.
Geoff F.

Re: Pre-Cat O2 sensor

Posted: Sun Mar 14, 2010 10:05 am
by stux99
Thanks for the quick response guys.
Mgmania is where I was looking.I will have a go :D

Stu

Re: Pre-Cat O2 sensor

Posted: Mon Mar 15, 2010 1:07 pm
by Rob Bell
Lambda sensors always seem to weld themselves in their threads in the down pipe. You're more likely to break your lambda removing tool than you are to actually getting the darn thing out. I suspect a bit of local heat, applied with an oxyacetylene torch or similar is the way to go...

Re: Pre-Cat O2 sensor

Posted: Thu Mar 18, 2010 10:08 pm
by stux99
Got my sensor today, one more question, will I need to take off engine cover to unplug it or can it be reached from below?
Thanks in advance

Re: Pre-Cat O2 sensor

Posted: Fri Mar 19, 2010 10:04 am
by Rob Bell
Best access will be from above Stu.

You're going to absolutely love this job. I recommend industrial quantities of tea and a lorry load of jaffa cakes. And more than likely more than one Lambda removing socket. And ideally a heat source.

Let us know how you get on, and what the grazed knuckle count ends up as :)

Re: Pre-Cat O2 sensor

Posted: Fri Mar 19, 2010 10:43 am
by bgunn
My advice? Take the manifold (if EU2/MEMS1.9/2) or downpipe (if EU3/MEMS3) off and put it in a soft jawed vice. You can get full swing at the sensor, and less likely to injure yourself..

Re: Pre-Cat O2 sensor

Posted: Fri Mar 19, 2010 11:11 am
by Geoff.F
A Lambda Removing Socket has a cutout for the cable connection. Cut the cable off and use a good quality long socket or if available, a cranked ring spanner. Fit new bit with Sensor socket.
Geoff F.

Re: Pre-Cat O2 sensor

Posted: Sat Mar 27, 2010 6:02 pm
by stux99
Thanks for all your advice guys, what a surprise :o
One tap and it came loose, did'nt even have to cut the wires.
So, plugs and leads and sensor done in 90 mins :lol:
I'm off for a Fursty Ferret now :thumbsu:

Re: Pre-Cat O2 sensor

Posted: Sat Mar 27, 2010 6:16 pm
by colintf
good result then Stu!

:thumbsu: