bigz28man

iTrader: (2)

I'm just double checking this to make sure that I read this right in the forum, the 02 sensors I need for my 97 Z28 should have the square ends?

Catmaigne

iTrader: (6)

You have 2 precat and 2 postcat sensors because your car is OBDII. The precat sensors have 4 inline wires in a rectangle pigtail and the postcat sensors have 4 wires in a square pigtail. Postcat sensors don't control the A/F ratio of your engine and aren't important (they're only there to make sure your cats are functioning).

bigz28man

iTrader: (2)

I'm running with hooker long tube headers and a ORY pipe....no cats, so with that being said I should need the square one?

LT1

iTrader: (1)

PCM needs the pre cat O2 sensor input.

For the post cat O2's you can run O2 simulators or have it tuned out.

Catmaigne

iTrader: (6)

Nope, you only need the upstream precat sensors with the rectangular ends.

BigBadWhitey

iTrader: (3)

Anyone know what the partnumber is the for factory replacements for the precat o2 on the 97?

madhatter

AFS75 is the Delco number

madhatter

BTW Amazon has them for $38

bigz28man

iTrader: (2)

I've heard Bosch sensors are the best or atleast many people have had good luck with them because others have burned out. Anyone have a part number of the Bosch sensor with the rectangular end? Also thanks guys for the info

BTC

I've heard just the opposite, and I recommend that you stick with AC/Delco.

BadBirdie

i also have a 97 lt1 does it matter if the sensor is heated or not?

JCSWS6

iTrader: (5)

Got my from amazon for a great price. 94+ all have heated sensors.

02v8ta

iTrader: (8)

NO.
Get the delco ones and be done with it. Many people on here as well as tuners/builders recommend them and nothing else.

sandman2100

iTrader: (8)

I got my Delphi's from Rock Auto for 78 shipped (2 of them) about two months ago. Replaced the crappy Bosch units that were in there from the previous owner.