I am trying to change this damn O2 sensor on my girlfriend's 90 TBI Formula and I don't have the right tools for it. I need to buy a wrench that will fit on it only I don't know the size. I looked in the repair manual but there is nothing and I would rather not buy a whole set. Anyone know this? It would be a great help to me. Thanks.

 

Go to the parts store and tell them that you need an O2 sensor socket, they will know what you need. Also you will need a long extension to get to it...

 

Are they all the same size?

 

as far as I know, all are the same size, the best tool to use is the sensor socket, but sometimes it doesn't fit in the space required, so you sometimes need a wrench, the dsize is 7/8

 

hehehe are you just too lazy to get under there and try out diff wrenches