this is for my friends '96 eclipse non-turbo:

he knows nothing about cars but tells me that his plugs fowl every 3 weeks or so... sounds like o2 sensors to me, what do you guys think?
i figured sensors would be like 30$ but they say theres 2 and are like 100$ each, does this sound right

 

yep there about 80 - 90 $ what all mods does he have ?

 

ouch!
no mods
does he need to replace both?

 

Maybe, but he's going to most likley need to replace the one before the cat conv. If his plugs and wires keep on fucking up, it could be for numerous reasons. Mine fucked up because of a blown head gasket, or in your friends case, the bad o2 sensor is giving the engine a bad case of knock or misfire. Replace the o2 sensor and the plugs with wires.

 

we'll give it a try, thanks guys

 

yeah, the "heated" sensor, (the one near the motor), is the one that usually ends up fouling. The one after the cat converter, (further down the exhaust pipe), normally doesn't have to be replaced.

He can get the car scanned at auto zone for free. If it's a fouled O2, he should be throwing a check engine light.

 

he's absolutley right!