Some people say run AC Delco AFS123 & some say to run AC Delco AFS98.

the AFS123 say they are pre-cats & the AFS98 say they are post cats.

i don't have cats so i only need the 2 pre-cats. i've been told they're the same sensor just the wires are different lengths.

these are going in an 02 camaro LS1 that i swapped into my truck.

can anyone enlighten my on the differences or tell me which ones to run?

 

I'd run the AFS123's if they are produced for a pre cat application... Is there an extreme price difference?

 

not much difference in price. funny thing is a guy on another forum post the specs that show the AFS98 being pre-cat.

 

from AC Delco's site

SENSOR ASM,HTD OXY
Part Number: AFS123
Product Notes:
Heated Oxygen Sensor (Position 2)
Pre converter ; Right hand ; SS, Z28
Per Vehicle: 1; Years: 2001-2002

SENSOR ASM,HTD OXY
Part Number: AFS98
Product Notes:
Heated Oxygen Sensor (Position 3)
Heated Oxygen Sensor (Position 1)
Per Vehicle: 1; Years: 2001-2002

the 123 says pre converter, rh & nothing for lh or position 4
the 98's don't say pre or post converter.

guess i need to know which sensor is which position.

 

It doesn't matter which goes where as long as the wires reach or you can make or buy extensions.....

 

so front or rear doesn't matter? i'm noticing they're both fronts on some vehicles & rear on others.

 

I didn't use factory gm ones when mine went, i used ngk (ntk is there electrical name i think from memory), they look thinner than the gm ones, but have never had a problem with them, they look identical to the Japanese cars like the honda's, etc.

 

The older GM parts were the "Thimble" style sensor. The newer style, even when bought as replacements from GM, are what is called a "planar" style.

I just bought new GM parts for my 00 Vette and they are made by NTK.

The planar style heat up quicker and use less heater current to run.

There is excellent info from Bosch, NGK etc on line if you search for Ogygen Sensor Design.

As far as I know, the fronts and rears on our cars are identical except for the wire length and connector style. I have measured them for heater current draw and they are identical.
However, the Corvette crowd will continually say to use the rears in the front when adding headers because they heat up faster and are more accurate without having an ounce of proof to back that up.

Ron

 

The reason some say per and post, is the wire length difference. As far as their ability to work where you put them, if the wire is long enough, they will work fine. The wire length is the only difference.

Ron,
some of the earlier Vettes had a flat 4 wire plug in the front and a square plug in the rears, so they couldn't swap those. So like you said, not an ounce of proof to that.

 

thanks guys!!!! that's what i was thinking. the guy that built my harness & tuned my ECU said he normally uses O2 sensors from a V6 camaro. i did some quick research on autozone.com & most the part numbers are the same for the V8 & V6.

i'll probably just buy another set of AFS123 sensors & go from there.

 

I went with the Bosch Vette rear sensors, havent had a single issue since. They had a nice heat shield on the wires & were long enough to get rid of my old worn out extensions too.

 

my harness has plenty lead for the O2 sensors so the length really isn't an issue. making sure i have the right one's is.

 

I missed the last part where you mentioned it was a swap in a truck, I'm guessing the harness plug is different than the Fbody plug?

 

i'm using a stand alone harness which has the 4 prong square plug. turns out 2 of the wires going to the driver side O2 sensor were crossed. switched the wires around & everything seems good so far. have to test drive it tomorrow.

 

So can the v6 ones work ?
I Swapped a ls1 in 01 Camaro, my question if front & rear 02 sensors from my v6 will work?

 

I'm running the corvette rears. I was getting slow response codes occasionally so I wrapped the collector and o2 sensor with header wrap to keep some heat in. Works great.

Did I mention that they were $32 bucks each on Amazon.com?

 

if the plugs are the same, chances are they will work fine.