hi all
i had a o2 sensor fault with my my99 uk,i replaced it with a second hand one from a 1998 wrx as i wasnt 100% sure it was o2 sensor!
anyway it has cured the fault (rough idle,smelling rich) but now it has a slight hesitation when cruising at any speed!under acceleration it feels fine tho?

i have also just fitted a sti topmount intercooler to!

its going to alan jeffery monday to be maped,would this sort it out???

 

Hi, I had the same fault on my99 uk, but the fault I was having the hesitation problem. The idle was fine.
I have since replaced it with a universal lambda/o2 sensor (£60) just to give it a go. Some people say they work fine, some don't. I've done well over 1500 miles and eveything is fine so far.

Thought I'd just let you know the problem I had. Good luck with it.

 

ok ideal thanks!im going to unplug it and go for a drive to see if problem goes!