LT1_King

how many O2 sensors would i need to buy for a 94 Z with one cat OBD1? and are they hard to replace?

bingo

Two O2s. They are not too bad. I think I removed one with a wrench and one with an O2 socket. I have only done this once on a 4th gen and it was last year. If they are original they might put up a fight.

OBE1 95Z28

Do yourself a favor and use AC Delco O2 sensors; people have had issues with other brands.

69gto96z

I used Bosch and am about to buy me a set of AC's.

EnerjetF67

I have Denso 02's and will not use anything else.
They are extremely tolerant of using leaded AV100 or Torco 110 fuels.

2000GTP

One of the 02 sensors gave me a pretty good fight, I had to soak it real good with PB Blaster and also had to heat it up with a torch before it finally broke loose. Removing the other one was quite painless.

LT1_King

do i need a lift to do this or is it possible to do it on jack stands? and what size of wrench and or socket would i need to do the job?

2000GTP

I'm pretty sure its a 7/8" socket/wrench size, I can't remember completely off the top of my head though. But yes, you can do this job on jackstands.

LT1_King

at the local auto stores they don't carry AC Delco they just carry the bosch and the denso. what would be better for the car? see i'm gonna do LT's in about a couple of months but for now which ones would i need to go with? and just about how long did it take you guys to do this?

Craddock

I have bosch and they suck, I might have just gotten a bad sensor, but the sensor I bought went bad within days. If you can't get AC Delco go denso.

Dave89IROC

IIRC, the Ac Delco ones are made by Denso, so you are good

2000GTP

Personally, I haven't had any trouble with the Bosch sensors, but with the problems that many others seem to have, it would be safe to stick with the Delcos. You can get them pretty cheap from one of these guys:http://shbox.com/1/4th_gen_tech2.html#Dal_and_Jason
The only reason I bought the Bosch's was because I didn't want to wait for them to be mailed because I was trying to get my car together quickly for its emissions test.