How To: Replace O2 Sensors

Since returning from our Corfu trip a CEL decided to make itself known, the code showed it to be one of the O2 sensors.

Not being one to mess about I decided to replace all three, (2 pre-cat, 1 after cat) also being of sound mind and body (including my wallet) and having bought sensors previously
HERE without any problems, I undertook this mammoth task myself (with the assistance of my friend Mike)

As usual I took a picture record of the procedure and I hope it will be of help to those of you who want to save a shed load of money on what is a relatively easy job.

The parts were ordered on line Tuesday 17th June and arrived the morning of Friday 20th June.

I opted for the 250-24200 Walker Universals at $49.90 each with shipping at $25.00 the total cost was $174.70 with no duty to pay giving a price in sterling of £88.50

The last price quoted by Mr T to replace one sensor was £215

Total time to replace all three sensors (including taking pictures) approx 30 minutes

One important detail I can report and that is after removing the top sensors my pre-cats are still in perfect condition after over six years and 65000 miles.

The sensors arrive well packaged with all necessary fittings

This socket is absolutely essential for removal and replacement

Pre-cat sensors (sprayed with release oil an hour before)

Removing is easy with the right tools

The old and the new

Wires crimped to the original plug

Heat shrink covers

After cat sensor removed easily from underneath the nearside rear (even with my quad pipes in the way)
Copper grease (supplied) was used when replacing the sensors and all appears to be working well

Hope this has helped to dispel some of the terrors of DIY maintenance

This documentation in no way replaces the Toyota MR2 Repair Manuals. The purpose of this content is only to provide supplementary information to fellow MR2 enthusiasts. Midship Runabout and its contributing authors will not be held responsible for any injury or damages that may occur as the result of practicing any of the methods or procedures described within this website. Article and photo submissions are property of the contributing author.

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2 Responses

  1. Andy says:

    Where is the after cat sensor located?

  2. Martin says:

    I’ve looked in that location for the after-cat sensor and there is nothing inside but smooth pipe. Any idea if the 2003 model has it located elsewhere?