what size o2 sensor socket do I need to change my sensors out? thought I remembered reading they were a special size but I have not found any unique sized sockets (other than the standard size)

1997 disco 1 just for clarification.

also just out of curiosity my CEL comes on for about a day once every 2 days then goes back off and the code is for the front right sensor, how bad do you guys think it would be just to replace that 1 for my emissions test next month and then wait for about another month or two to do the rest? ($100 each, plus the emissions test, plus registration costs, and my 6 months insurance policy is all due next month so the budget is a bit tight!)

 

You are correct, o2's on my d1 were 17mm,not a standard size. To remove them, I found a wrench at autozone that was for a/c lines or something. its like a 17mm box end with a notch cut out it. worked great. From reading other posts everyone will recommend replacing in pairs, as an old one and new one mixed will give false readings on one side.

 

How many miles on that 97, what exact fault codes are you getting?
There is also a special socket made for 02 sensors that is made to fit around the wires, an open wrench is good though.

 

X2 on the size. If you do not replace all of them, you might throw a code for a side, and if only one side, the mixture will not be right because you will be reading lean and rich on either side.

 

i cant describe things to well. $8 at autozone

 

dont remember the code but it was for the right front (precat) sensor my main concern is passing the emissions test, I was thinking maybe just for now trying to get it tested while the light is off but I am concerned with my luck the light will come back on as I am pulling into the testing facility!

Mike it has around 138k witch about 8k of that is from me, I am not sure about previous maintenance however the guy I bought it from had 3 or 4 rovers and told me the maintenance was done routinely (and the truck has run pretty well since I got it)

just on a side note there could have been other sensors already replaced for all I know, and the light is VERY intermittent, I plan to try to clean the connector on that specific sensor but it appears to be somewhere over the transmission so I have yet gotten in there to do so.

 

The connectors are on top of the tranny, I had to remove the ignition coil packs to access them when replacing my fronts.

 

is that the easiest way to get to them? and what is involved in removing the coil packs?

 

It's the only way 'far as I know. I used masking tape, labeled each plug wire, disconnected 'em all. Then there's four nuts holding the bracket with all the coil packs on it. If I remember right, 2 of them needed a pretty long socket extension to reach. It was pretty easy though