Oxygen Sensors Replaced

In my continuingly futile attempt to squeeze a couple miles more per gallon out of the 2003 Discovery, I felt some maintenance was due. As you may have read we are taking the Disco on our trip to California this summer. And doing what I can to get as good a mileage out of her as I can considering 4$ per gallon gas seems reasonable.

I managed to get some good weather in the neighborhood. Or as we suburbanites call it...the hood. It really is a nice neighborhood. I checked the temperature just for a reference and to blow some more time while the engine compartment cooled. It was a lovely 88 degrees or there about in the shade of the garage. I know some of you Northerners may see 88 degrees and freak out. But in Okieland that is a reasonable temperature for June 10th. The clouds and wind have everything a bit cooler. Consider in just a month or so we will be in the middle 90s. We have already hit 100 once this year back in May so its a safe bet for a hot summer. I fired up the 1967 Westinghouse fan I keep in my garage just for some air moving through the workspace. It's got two settings, mild and hurricane. I leave it on mild. You can see a good part of two of my camping kits behind it on the racks. The one on the left is modern camping and the cases on the right are for my historical camping. I know the garage is a cluttered mess but you should have seen my last house. For more on that check out the entry for tie rod replacement. Wow.

I got the sensors and my plug wires and spark plugs through Atlantic British's sale this month. They are discounting the tune up stuff to get folks going toward conservation of fuel where they can. This works for me and I got some minor tune up parts. I also bought the air intake gasket so I could just remove the intake to get to the ignition wires. The coil packs are tucked tightly under the shroud on top the engine in the back. Completely unreachable except for people with really tiny hands or elves. I am told this is a not too fun job with out the plenum removed. At this point I want you to imagine me standing in the queue to hell, where surely the engineers will be that put that in the back of the engine. Remind me to kick those guys in their nut sacks.

But I digress, on to the sensor swap. Here is a nice image of the new sensors. On this model there are 4 sensors. Two each, pre and post of the catalytic converters. I opted to replace the rear ones first as they are easier. You can see their locations in the following links. Rear right, rear left, and one of the front ones.

I began by disconnecting the plugs to the sensor as I extracted the old ones. The two in the rear were relatively easy but the front ones were a bit of contortionist fun to complete their extraction, mostly due to the location of the plugs. (and don't forget to remind me again that guy needs a kick too).

With a little effort on each one I got them out and replaced them with the new sensors.

There are a couple of difficult spots to route to including one were the sensor leads are wrapped under a well placed hose. It was difficult to get the new one under the hose. But while extracting the old one, which I almost cut, in leiu of struggling with it, I left the old one to hold up the hose while I slipped the new one beneath. I could have used a zip tie but I stuck to the way it was delivered.

I was working on one of the sensors when I heard the camera go off. It must have wanted to take a pic of the fuel cans and the screws and bolts rack. Weird.

This was about an hour and some change to do. You should also consider during this project I also took pictures for this site, cleaned the air filter out with the air compressor, finished up the oil change and cleaned up a bit. On the Difficulty Scale it rates as a 1. Mainly because it was not technical at all and only required only 3 tools. The physical problems of reaching the plugs weren't near as bad as I've seen other places so that played no factor.

Thanks for reading and happy Rovering.