Rusty o2 sensors VS

[m_brown_10]

Hey decided to change my o2 sensors today to see if i could get better fuel economy
when i pulled them out they where not very good looking they have a reddish rust scale on both of them and are also half coated white half black
guessing they have seen 200k so just wondering if this is normal for sensors of this age?
also bought Bosch ones but the head is smaller and has less slits in them is this going to be an issue?
read a post that possibly head gasket may be stuffed because of rust, also have very slow coolant leak will need to top up overflow every few weeks but i have some top hose issues at pressure
Exhaust seems normal no big clouds of anything just slight puff of steam any help would be great Attachment 123063 Attachment 123064Attachment 123065
sorry the pics are not that special

[m_brown_10]

Also if anyone is wondering they are really easy to change over couldn't find my 22 spanner so did it with a 200mm shifter and a hot exhaust cant see why you would need a special tool/socket, hardest part is reaching under drivers side of the car to unclip it
new Bosch ones from Repco cost me $126 after RACV Discount hope this helps someone save the $60 Repco wanted for the tool (i was going to buy it after reading some of the posts on here but it was out of stock luckily)
Also if you cut the wires off before you take them out it will help as they just get in the way and make unscrewing annoying

[James39]

I got two bosch sensors for $92

[m_brown_10]

pretty cheap any idea on the rust?

[VSSS_5L]

I've only really seen the sensor side of o2 sensors covered in soot not rust. If your car's done 200,000k's, and you've taken the thing out to look at it...replace it... Might give you a mickey whisker more fuel economy with the new one in it.