I got engine warning light on and picked code 21 off the dash. Does anyone know the part number for an ae101 gze o2 lambda sensor and or where to get one. Mr T quoted me £160 inc VAT, hardly peanuts. Autogateway have them at £77 but I don't know if they are the right sort.
Please help.[/i]
If you're prepared to get one from the US, twosrus.com have a Denso one for $70. It's listed as being for an MR2 SC so you might want to check whether the AE101 one os the same.
I had to replace the O2 sensor on my 4A-GZE this year after getting fault codes for the old one.
O2 sensors only come in 2 basic flavours so you have a lot of scope to try different ones, so after a bit of research online, I got a brand new Bosch 4-wire one off eBay for less than £10. It is a screw in type so after thinking about making an adaptor for a few weeks (usually while sitting in the pub), I bought a boss for it from some online supplier for about another £10. The whole thing cost about £20 and is at least as good as the Denso product and looks a lot tougher.
You need to ignore the heater leads, IIRC they're the 2 grey ones. You also need to make up an earth connection because the Denso 1-wire job uses an earth return through the chassis. I found it was best to run a shielded cable all the way back to the ECU because you will get a cleaner signal this way and with the O2 sensor this can help.
After that it has worked really well and saved me a bundle. Also, having the boss adaptor means I can use a range of other O2 sensors if needed.