The MR2 Owner's Club of New Zealand

I've got a dud O2 sensor in the MR2 making my fuel economy horrendous. As the exhaust is rather old the nuts holding the sensor in place are rusted too much for normal sockets to remove.

I was wondering if anyone had a 12mm or worst case an 11mm nut extractor I could borrow to remove the old nuts so I can install another sensor with new nuts?

I'm in Wellington.

rocco26 has let me borrow his set. If they work then awesome. There are 2 types.

This is what I have to use right now which works well on nuts or bolts that still have some shape. These nuts seem to have lost their shape due to rust. This type may work better but I'll see how I get on.

The heads will shear off before you will get a chance to turn them
drop the exhaust out and I can sort it at work .

Thanks for the offer Colin. Removing the exhaust from an SW20 either needs the subframe dropped or the car lifted up really high of which a proper lift machine is needed. Plus the 2 gaskets to the manifold are $41 each. Ouch.

I did manage to get the rounded nut off my spare exhaust just by tapping the socket on with a hammer. Luckily they are a lock nut so the top of the nut is really the only thing holding the nut to the stud. Once it is cracked the nut comes off really easily. I think my main issue will be actually accessing the nuts and getting a socket and wrench in there. Maybe it's easier than I think as I was focusing on sorting out something else last time I looked under there. A job for next weekend.

I was thinking it was a bolt
studs and nuts are easier to sort

I don't know what I was complaining about. Once I figure out how to reach the O2 sensor nuts I swapped out the sensor for my spare in a short time.
Turns out Toyota actually placed it in a reasonably clever position for how far down the exhaust it needs to be. You just need the right amount of extensions on your wrench to get to it from the wheel well.

Thanks for rocco26 for letting me borrow his nut extractors. Full description and photos on the process here.

http://mr2.org.nz/phpbb3/viewtopic.php? ... 54#p142654