Ciscokidd

Greeting pals and gals, i am a new user in dire search of wisdom.
I recently purchased a 94 Z28 M6 with various mods on it. Chevy Hot Cam kit, 1.6rr, Hooker headers, Hooker exhaust, Racetronix fuel pump, and the MSD opti-spark 2, Hurst speed shifter. Anyway my problem started when my passenger side header burned through my o2 sensor wire. No problem right? Wrong! I bought a new sensor, but the guy at the parts store was as confused as i was. See my car has 3 sensors. Two on the passenger side and one on the driver side, all pre-cat. Two are 4 wire and one is 1 wire. My question is, does this sound right, does it matter where the 1wire-4wires goes? Car starts up fine and runs like a bat out of hell for the first 20 min. after it starts to sputter and bog down. Any advice would be greatly appreciated!

RamAir95TA

iTrader: (2)

Your 94Z should only have two 4-wire O2 sensors, both pre-cat, one on each bank. If you have three, where is the third one located? Perhaps the previous owner hooked up a wide-band O2 gauge.

I would be weary about picking up O2s from the parts store. When it comes to engine sensors I prefer GM AC Delco parts.

Are you throwing any codes?

Ciscokidd

Well the way it was set up, on the passenger side the 1wire sensor is on the header. The 4wire sensor is on the exhaust pipe before the cat. The driver side is a 4 wire and is located on the header. As far as codes are concerned in sure i am getting one although my scanning tool is a POS. Can i just illiminate the one wire and move the 4wire up to the header? Thanks for your help!

RamAir95TA

iTrader: (2)

Yep, get rid of the 1-wire sensor and move the 4-wire sensor where it needs to be and see if that helps.

What is the 1-wire sensor hooked up to?

Ciscokidd

To tell you the truth my friend your guess is a good as mine. I've pulled the ECU Out and traced the wires in the harness. Only loose wire has a one prong female connector and runs into the inside of the car. I however do not see where it goes to. the care doesn't have any mods or guages inside.:,(

djjab57

iTrader: (17)

Maybe they hooked up some kind of exhaust temp gauge ? Is the an extra temp gauge inside the car ?

Ciscokidd

No, just the stock gauges in the dash is all. Am i on the right track though, with the O2 sensors and the sputtering problem?

WhyHelloOfficer

iTrader: (5)

Sounds about right. Get the correct 4-wire O2 sensors in each collector where they should be.

When you install the new sensors, make sure that the wires and harness are tucked/zip-tied/strapped away from any sources of heat, or you are going to have the same issue again. From the factory, the O2 sensor harnesses are pretty secure to limit their movement, you should ensure the same.

Also -- be weary purchasing O2 Sensors from your local DAP. Historically people have had issues with the Bosch O2s that are usually sold locally. Like it was mentioned earlier, go to the dealership and get AC Delco brand ones, or order them online.

If you will be ordering them online, also check out the NTK (NGK) O2 Sensors. I ran them on my car for over a year without a hiccup.

Ciscokidd

Ok ill look into some AC Delco's. Thank you guys for all your wisdom! One more thing, could anyone suggest a good tunner? I would like to get the ECU reflashed for the upgrades made on the vehicle. You guys are awsome!

djjab57

iTrader: (17)

cheapest place to get them is here that i could find $62.10

http://www.gmpartsdirect.com/

RamAir95TA

iTrader: (2)

I recommend PCMforless.com. Been using them for 9 years now.

Others will recommend madz28.com though. Both will provide you with good results, but will be no substitute for a solid dyno-tune.