[svx1999]

O2 sensors on the SVX are common.. replace in pairs and to the one mentioned the spray on oil.. He's telling the truth.

THe one on the passenger side is the bear to change out mainly the connector since it's in a blind spot.
and as for price.
I know I din't pay anymore then 70$ a piece for mine and that was a Subaru Replacement.
of course that was back in the Days of Larry At Cor Dalen.
in WA. He was great and very helpfull too bad WE can't get a Replacement for him..
hint hint.

another thing I have noticed about the SVX... If your car has been running fine and starts to idle a lil poor or run a lil foul.
Take off the air tube remove the egine cover that says ( boxer)
and spray some Carb cleaner on the throttel plates Does wonders. just make sure you put all the hoses back..

Just spraying out the throttel body has done vast improvements on my car.
open up the throttel and spray it down the throat! DO NOT empty the entire can or get too spray happy.
Your car may run rough for a min until all the cleaner is burnt off.
as far as my experience has been, every once in a rare MOON I will get a check engine light. Usualy I pull a Diagnostic code so far it's always been O2 sensors.
my guess is, they are either not warmed up and are giving a false reading back to the computer which throws the CE light.
it always goes away.
the O2 sensors are easy to spot. just look mid ways on your exhaust , you will find them, it's the only thing that has a Wire connected to it on the exhaust system.
Right as it starts to V off..

Also check fuel filter , air filter, sounds to me like things are just dirty.. Get some BG44k injector cleaner that also works wonders.
BG products can be found at most any dealership.

Happy Drive'n
Svx1999