oxygen sensor

[chevyguy3766]

okay so i seafoamed my engine tonight. everything went fine. i drove around afterward and my checkengine or service engine soon light was on i can remeber what it said anyway my guess is that the O2 sensors are dirty. well about an hour later i drove some more and the light went off. i know if you have dirty senors then you can kiss your gas mileage goodbye. my question is that even though the light is not on anymore, should i go and buy new sensors?

 

[96cherry]

i dont have any o2 sensors and havent noticed any change in my gas mileage

 

[jbenson]

im throwing two o2 sensors now and haven't noticed any less miles.
have you checked prices yet? that's why i haven't changed them yet but im gunna try cleaning them first.

 

[fyremanpat]

You have FOUR O2 sensors...TWO upstream and TWO downstream. You cant clean them, only replace them. They will run you roughly $40-$60 a piece...BUT before you replace them, clean your MAS with MAS cleaner first. After doing mine I swear by it. As far as bad mileage it depends on the reading the computer gets, but you will have a rough idle. Also cleaning the MAS will help with this. Hope this helps

 

[chevyguy3766]

what is the MAS and where is it?

 

[96cherry]

thats your mass air flow sensor , that flex tube that runs to your air filter, the aluminum thing in the middle, it gets a build up over time but be careful when cleaning, brake clean works well

 

[jbenson]

You have FOUR O2 sensors...TWO upstream and TWO downstream. You cant clean them, only replace them. They will run you roughly $40-$60 a piece

i was told you can clean the two down stream on the exhaust cause one was $80 and the other was $120. is this wrong?

 

[fyremanpat]

An O2 sensor basically is a resistor, the computer reads OHMS sent to it from the O2 sensor...if these go bad you cant clean or fix them, simply replace them. You will find different prices everywhere you look. Generally the up stream are a few bucks more... And as far as cleaning the MAS, spend the money and get the proper cleaner for it...I found that out the hard way. Im sure brake cleaner works because it doesnt leave any residue, but I wouldnt chance it....MAS are not cheap and dont touch the element inside of it with anything.

 

[95TwinTT]

An O2 sensor basically is a resistor, the computer reads OHMS sent to it from the O2 sensor.

The O2 sensors create current. Their operating range is from zero to 1 Volt for most versions. They are not a resistive device.

O2 Sensors should always be replaced if suspect. Cleaning is not practical. The mileage loss or the damage that can be caused by a damaged O2 can be more expensive than the replacement of the O2's.

 

[fyremanpat]

Yea what he said...my bad. I guess I was thinking about something else