I just got a CEL (0303 left front), i had this come up about a year ago, but it went away. Recently, I have noticed a drop of about 4mpg. Would you recommend replacing all three sensors at the same time, or just the front two or just the one that gave the error. Is it true that downstream sensor DOESN'T effect gas mileage?
thanks,

 

I would replace both since you have a 95 if you havent had them replaced already in the recent past. 95-96s only have 2 O2 sensors whereas the 97-99s have a third behind the cat. Only case I believe your mpg would not suffer is if it were that third one behind the cat on a 97-99. BTW, Go State!

 

This is not true, 95-96 also have 1 by the cat as well.

 

Definately replace all 3 sensors, especially if you have high mileage. You'll change 1 and then 2 months later another one will take a ****e.

 

Thats right, I forgot they had one in the cat as opposed to behind it. Been awhile since Ive been under a 95-96

 

if the other sensors are functional why replace them? Replace the faulty one, reset the ecu, continue driving the car. the o2 are not hard to get to at all and takes about 20 min to change one.

Save the money and wait till it goes, then change it.

 

Thanks for the response...I think I might just go ahead and replace the faulty one and see if that helps...

Good call on the Wolfpack!

 

Replace all 3 sensors. If one failed, the rest are on their way (and you have a 95 which is not so new). I bought all 3 and saved on shipping.

Here is the link to the seller I bought from (highly recommended):
http://search.stores.ebay.com/GLOBAL...271212QQsofpZ0

 

If you choose to do all three, I have a used set for sale (all with less than 36k)

 

What ever you do... DO NOT buy used O2s as offered above.

 

98 rear O2 is incompatable with 95 vehicle.

 

there's a fuse inside the car for the O2 heater. Make sure its not blown..