O2 sensor question.

[heavyredchevy]

Does it matter if I move the O2 sensor downstream to right before the cat when it came stock on the driver side manifold? It shouldn’t right? If anything it should be better because it’s now reading both banks. But ever since I did this just after I bought the truck I have this random hesitation. It only does it when it’s warm which leads me to believe that it’s the O2 sensor. I have replaced or checked all other sensors. I have also checked the EGR sys.

[FearlessFoe]

yeah.. the headers really dont heat up enough to get the one wire o2 sensors workin.. so if you havent already, upgrade to a three wire sensor.. also, the further back, the better the sensor will read. There are exhaust pulses which smooth out as they travel down the pipe. Usually right before the cat is the best place for the sensor. HTH

[ktisdale_2]

Originally Posted by FearlessFoe

yeah.. the headers really dont heat up enough to get the one wire o2 sensors workin.. so if you havent already, upgrade to a three wire sensor.. also, the further back, the better the sensor will read. There are exhaust pulses which smooth out as they travel down the pipe. Usually right before the cat is the best place for the sensor. HTH

Where can you find a really good aftermarket 3 wire O2 sensor. I have a '93 with a 350. Thanks again guys!

[FearlessFoe]

aftermarket=bad.

go to rockauto.com and order AFS74 (ACDelco 3 wire oxygen sensor) $45
Also, to make a nice setup.. you can order 85393 (Dorman 3 wire weatherpack) $6

I just finished with this setup.. not a single problem.. seems to have increased my mileage about 2-3? mpg

[heavyredchevy]

I couldnt find the 3 wire kit there.

[FearlessFoe]

Its not a kit.. just a weatherpack connector and a oxygen sensor.. you have to wire it in yourself

my truck just went from 15.5 mpg to a little above 18 after changing just the oxygen sensor so i cant complain

[Bob B]

Fearless said:
My truck just went from 15.5 mpg to a little above 18 after changing just the oxygen sensor so i cant complain[/quote]
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Hi, What was the original reason you replaced the sensor?
Was it giving errors?
Bob B

[Bob B]

Originally Posted by Bob B

Fearless said:
My truck just went from 15.5 mpg to a little above 18 after changing just the oxygen sensor so i cant complain

-------------------------------------
Hi, What was the original reason you replaced the sensor?
Was it giving errors?
Also what year/model/engine truck?
Bob B

[1968 Pontiac]

I have the one wire o2 sensor, but want (need) to install the three wire. What wire would go to what. I'm guessing, but does:

1 go to the existing o2 wire
1 go to switched power
1 go to ground

Terminals are usually identified with A. B, C, etc.

[heavyredchevy]

Yes, please specify how you did this.
That sounds about right 68pontiac.

[1968 Pontiac]

I found a link which ID's the wires for pretty much any O2 sensor made:

http://home.earthlink.net/~jcgebhart/o2sens.html

I found the above link at the following site which seems to have some usefull info for anyone wanting to convert their carbureted vehicle over to TBI:

http://home.earthlink.net/~jcgebhart/msindex.html

[1968 Pontiac]

Does anyone have ideas on which wire would be easily accessible to splice into for power to the heater on the o2 sensor?