I had an 'old' AEM UEGO wideband O2 sensor that only read from 11.0:1 to 17.3:1 a/f.

I purchased a 'new' AEM UEGO wideband O2 sensor that will read from 10.0:to 18.x:1 a/f.

I wasn't looking forward to installing the new guage/sensor because of the amount of work involved, so I started looking at things. The O2 sensors are identical, and both have the same plugs. However, I swapped the O2 sensors because the new one was new. The harness is about 10" from the sensor, so it was really easy to swap just the O2 sensor.

While I was under the car I looked at the 'old' harness and compared it to the new harness. Luckily, they match up perfectly.

I then removed the 'old' guage and cut the wires about 6" from the guage. The 'old' guage doesn't have harnesses on the back, so you have to cut the wires.

Next, I cut the 'new' harnesses off with about 6" of wire on them, and soldered them, color to color, with the 'old' wires.

I fired the car up and everything worked perfect.

I figure I saved about 2-3 hours of work by not taking the battery out, cutting all the wire ties, and pulling the old wiring harness out. Also, since I use the old harness I didn't have to reroute the wires through the interior.

All and all, I wasn't looking forward to installing the new guage, but it went it rather quickly (less then 45 mintues), and works great. I'm sure there are other people in my situation that could benefit from the wider range of the 'new' sensor!

I purchased the new sensor from Forged Performance - great price, and stupid fast shipping (I ordered it yesterday morning thinking I would get it next week, but it came today).

 

Good to know I have the "new" version. Didn't even realize there was an older one, so I guess I dodged that bullet...

 

hey thanks for the write-up. I may upgrade someday. Not sure I'd want to cut the new units wires though
Does the newer version have the same serial port wire? I use it for tuning the UTEC.

 

Yeah, it is exactly the same. I use the serial output as well and didn't have to change anything at all to make it work.

Wire would you be hesitant to cut the wires? They're only copper, and go back together really easy.

I bought mine probably 2 to 2.5 years ago. I've been FI for a while now!

 

IIRC, the new UEGO has a connector on the back. I just wouldn't want to cut that harness up if I could avoid it. Not worried about soldering

 

Yes, it does have a connector on the back, but the old one doesn't.

Your choices are to rerun the entire wire throughout the car and engine bay, or just snip it off and solder it to the old wire. All to colors match up, so its simple to do and would be almost impossible to mess up.

I then soldered the 'new' wires to the 'old' guage and sold the guage to a friend.

I'm not sure how everyone else has theirs installed, but like I said I would have to take my battery out to get to the place where I ran the wire though my ECU grommet (G35). After I ran the wire through there I sealed it up with silicon so water wouldn't leak in. So, it would have been a nightmare pulling the old wire out just to run the exact same wire back through.

 

On the G35, you have to remove the battery to get to that grommet? What a PITA! The Z is easy, just pull off the battery cover and the plastic piece that goes up against the windshield and you're there.

 

In order to get the grommet sealed back up you would have to. Otherwise, you could just fish something up there (or use the old cable). I found out the hard way that, if not sealed back up, it will leak.

 

I am about to attempt this and i was wondering on the power side there are 7 wires and 7 on the sensor side correct? I beleive on the new version its 4 for the power and 7 for the sensor..did you just not connect the other 3 wires on the power side.. it should be red 12v, black ground, blue serial and white 0-5v correct? please let me know what you did about the wiring thanks!

 

There are 6 wires for the O2 sensor and 4 wires (power, ground, serial out, and analog out) on the power side.

I did a bit more 'research' and found that the old units and the new units both have the EXACT SAME PLUGS ON THEM. However, you have to pretty much destroy the old units to get to the plugs.

What are your plans for the old guage, I would be interested in purchasing it from you, if the price is right! I only need the actual guage housing, not the O2 sensor, so you could keep it for a back up.

 

The gauge I have is 7 wires on power side and 7 wires on O2 side do i not use 3 wires on power side and 1 on O2 side? i beleive on the o2 side the orange color wire fell off the harness....so my assumption is that the power side is the same colors r,b,bl,w and the o2 is all the colors minus the orange?

the weird thing is i actually was just trying to cut and rewire them since it has no harness but the thing would no longer power back up....connecting red to +12 and black to ground should have yielded a power up of the unit which it was not doing.

 

I'm not sure about that. What is the part number of the guage you currently have? It may have been designed for a different wideband. The first thing I would do is make sure the new O2 sensor will plug in to the old O2 sensor plug down by where the sensor mounts in to the exhaust pipe. At that junction you can verify the existance/usage of wires, then compare that junction to your harness.