I'm running long tubes now and the oxygen sensors are quite a bit further down the exhaust stream than before.

This concerns me because my BLM's have became irratic, good tuning but large splits at idle. This is with absoulutly no exhaust leaks and brand new GM sensors. No vaccum leaks either!

Anthor issue that concerns me is that my car sometimes switches back to open loop at long stays at stop lights. This kinda makes me that the O2's are going cold and the computer realizes this. I do not remeber the car ever doing this before.

What do you guys think? Are any of you runing heated o2s? What would you tap power from to use heated o2s? Are they designed to have powerd up heaters all the time?

 

I run a heated O2 sensor on my shortie headers. I noticed that it keeps my BLMs more constant then the stock O2. Another thing I like about the 3 wire is you can set your ECM to go into closed loop much faster with a heated O2. On long tube headers you really should be running a 3 wire.

I noticed this happened with my car (probably b/c O2 sensor was old), one of the reasons I switched to a heated O2; now my car only goes into closed loop after it has been ideling for an extended amount of time.

 

Sounds like you do need a heated O2.
I am running one currently. I have it wired into the ignition switch so when the key is in the run position it has power.

 

What is the part number of the O2 sensor?

 

Sorry, no part number to give, it came with a Dakota Digital Air /Fuel guage I bought years ago and never installed.

 

Go to the auto parts store and get an O2 sensor off a 91 corvette ZR-1. If they give you an O2 sensor with 3 wires then that’s the right one.

 

Thanks, that will work.

 

bosch 12375 4 wires work the best.

 

I tried the ZR1 sensor and had no luck with it. The voltage range was in the 1000Mv area. This threw the ECM off. I ended up getting one for an Astro Van, which seems to be working well.

 

It was a bad sensor or you hooked it up wrong, the ZR1 sensor does work on thirdgens if hooked up right.

 

Well I was almost positive that there was no difference between O2 sensors. I hooked up the Astro van sensor exactly like the ZR1 sensor and it worked fine. I guess the ZR1 sensor was bad, but I just wouldn't expect those kind of quality issues from Bosch.

 

I used to work at a reed lallier cheverolet used car dept., and I can tell you that we have replaced around 10-15 bosch o2's which where brand new while i worked there.

It happend so often that we always had a new joke when a mickey mouse O2 came in.

 

Does anyone know the part number for the connector on the wire harness side for a 4 wire O2? I am pretty sure it is a male ending.

 

Can anyone tell me what car a 4 wire O2 came on so i can get one at the parts store.

 

BTW, the Ford Taurus SHO's have 3 wire bosch heated o2 sensors. Mine's been working without the heating element hooked up for about a month now. I've gotta get under there and hook up the heater wires but I've been busy with other crap like SCHOOL (damn I hate being back).
Seriously though, shop around for a heated one, mine is used and was assumed to be broken.

 

What car did the 4 wire come in though?

 

Anyone? Anyone? Don't all volunteer at once now.

 

http://www.diy-efi.org/gmecm/compone...2_sensors.html

Here you go Ben Stein. It doesn't show an application, just a part number and description. Personally I would get one for an Astro or a Jimmy with a 4.3L Vortec (vin W) from 92-94? These are three wire o2's but are cheap. I think something like $25 through Delco.

 

Thanks guys! Maybe this is some of the problem with me car and the new motor. The BLMs are going crazy... we can't even get teh injector constant set right to make them go up or down like they should. Guess its worth a shot for $25 from Delco. THX again!

 

Well, did you have any luck with the BLM's and the heated o2? What about using a 3 wire heated o2 from a 95' Full size chevy truck with a 4.3 V6? If it will work, I have a spare one of those. Reason I'm posting is that I have LT Headers and I have no idea if the ECM is acting up (no codes so far though). I'm using an Ed Wright chip custom made for my combo. Let me know, cause if it will make a diff in power or response, I will wire up the 3 wire o2.

thanks,
Mike (1bad91Z)

 

Anyone got a wire diagram for the astro or jimmy 3-wire O2 (so I know which wires go where). I'm switching to LT's this weekend and might as well do it right while I'm at it

 

Yeah, anyone have a diagram? Also everywhere I check they are like $50-$60 for these "cheap" 3wire o2's. Where is everyone getting them so cheap? THX

smok'nZ28- you're from Festus??? I'm not too far away. Whats your name?? I know alot of ppl from up there. Later!

 

The signal wire should be black (usually) and the heater wires should both be white (usually).