are o2's necessary if....

[jiveass]

if i have long tubes and no cats and no egr system.....would i need the o2's or not?

[GoldenFlame]

You Need the front o2's that go into the Headers, but you won't need the rear ones

[pajeff02]

^^ This. The front O2's control fueling in closed loop operation.

[jiveass]

glad i asked this question....was gonna run without em cause the headers came with bolts that plug the o2 holes.....

[jiveass]

will they need extensions? or no

[pajeff02]

Unless you have the long harness sensors already, you'll either need extension harnesses or a new set of Bosch 13111 sensors.

[BashamWS6]

Unless you have the long harness sensors already, you'll either need extension harnesses or a new set of Bosch 13111 sensors.

this. some people have trouble with the extentions

[GoldenFlame]

I'd shell out for the Bosch o2's if your budget allows.. My buddy has extensions and his SES light is on all the time.. Car runs fine, but the code reads front o2's

[Firebirdjones]

Some people have issues with the extensions, but I have no idea as to the quality of extensions these people are running, or how they are routing them. I've seen some pretty hokey extensions that come with headers and you basically have to solder them together. That's just asking for problems.

With that said, I've used a very nice set of 02 extensions on both of our 4th gens for years and never had a single issue. They are well made with GM style weather pack connectors and wiring insulation just as you would see on an 02 sensor.
Honestly though, if the car hasn't had the 02's replaced in a while, I'd take Goldenflames advice and get a new set,,,while your at it just get the bosch 13111's with the longer harness and forget about the extensions. It eliminates the extra connections that are unecessary. Fewer connections means less possibility of problems if they should occur.

[redbird555]

Yup what he said^^ with the miles on the car you pcould probably use a new set anyway although some people have probs with the bosch sensors myself included. I did denso sensors they are the same price and are now oem on gm cars so why not? A few people have also been doing this its free and easy but i havent done it myself... Basically your switching the front pins with the rear ones on the pcm therefore you can simply plug in the front o2 sensors into the rear harnesses and they will work like you plugged them in up front.

http://chevythunder.com/1999-2002%20...%20pinouts.htm

"Take the 1 screw out of the blue connector, then use a small screwdriver to pop the grey cover off of it, and to pop the blue parts off as well, the releases for the grey cover are obvious when you look at it, you do NOT need to take the screw out of the connector to get the grey cover off, (you need to snip the small zip ties and re-do them later) and the blue pieces are held on by tabs on the ends...just put the ends in slightly (where white sticks through them) and they come right off...the pins then pull out towards the wire side when you pull the white lock tabs ever so slightly away from them. In that blue connector, swap the following pins:

25 swaps with 26
28 swaps with 29
65 swaps with 66
68 swaps with 69

Thats IT...put the blue pieces back on, put the grey cover back on, replace those small zip ties, make sure the orange gasket is seated properly to keep water out of there, and bolt the connector back onto the PCM. Plug your front O2's in to the REAR connectors under your car...get brand new stock O2 sensors for your car and plug them right in.

THE HARDEST part of the pin swap, is getting the grey cover off of the PCM connector...and with a small screwdriver or pick, that is a fairly easy task. Northern cars/trucks tend to show a little more corrossion on the metal body of the plug which makes it harder to get the cover off...but with patience (and 3 minutes) it comes off." from ls1tech

[shady milkman]

grab some 13111..

[WICKEDLS1]

the only way you could get away with deleting them is with a speed density tune but you would also have to get rid of the MAF too

its alot cheaper to buy the o2's then have it tuned like stated above