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So as stated in one of my other threads my rear o2 sensor doesn’t read anything. The sensor itself is good when swapped with the front. I remember reading that it was an issue with the first ecu adapter harnesses, that I have. I was wondering if anyone had the CORRECT pin out. I’m guessing the wrong one has been posted before and I don’t want to look at an incorrect one.

Coop

[quote=""DCIV""]So as stated in one of my other threads my rear o2 sensor doesn’t read anything. The sensor itself is good when swapped with the front. I remember reading that it was an issue with the first ecu adapter harnesses, that I have. I was wondering if anyone had the CORRECT pin out. I’m guessing the wrong one has been posted before and I don’t want to look at an incorrect one.

Coop[/quote]

If I remember right, it was wires in the adapter harness going to the wrong pins. I believe the chart below from stealth316 is correct. I think all the 98+ ECU that work have the same pinouts. Remember, the pinout is when you are looking at the back of the connector.

http://www.stealth316.com/2-ecu-terminals.htm

Man aaron! I owe you a beer, not only did I need that exact pin out numbers....mine are reversed.

Now I assume these connectors are made to come apart? Can I swap them that way or do I need to cut them and swap them?


Coop

[quote=""DCIV""]Man aaron! I owe you a beer, not only did I need that exact pin out numbers....mine are reversed.

Now I assume these connectors are made to come apart? Can I swap them that way or do I need to cut them and swap them?


Coop[/quote]

They do come apart. If I remember right there is a little slot when looking at the female end of the connector. You have to get something in there to release the locking tab of the small metal pin.

This video should help with what I'm trying to explain.


https://www.youtube.com/watch?v=CFM-6ovP_-k

A small screwdriver can work but they also make depinning tools. IIRC Harbor Freight might even sell some.

That's the old style connector in the video. The newer JAE connectors are a little different. I think you actually press down on a metal locking tab to release them. It's a giant pain because they're so touchy.

I actually bought a depinning tool kit off eBay. It's SO much easier than the janky hand made tools I had. I was able to break down my Montero Sport harness in a few minutes.

yeah....link to that tool jeff?

I have been over here attacking it from the wrong direction. Now I realize even the tiny....and I mean tiny screw driver I have is too big. It can't open up bigger like a screwdriver does, it needs to stay flat.


Coop

https://www.amazon.com/Terminal-Removal ... moval+tool

This work? I am looking at stuff on amazon that I can get prime two day shipping so I can work on this over the weekend.


Coop

That might work. I'd have to measure the tools that work for the Mitsu connectors.

I got this kit. Though mine was red, and I didn't pay nearly that much.

https://www.ebay.com/itm/8milelake-23Pc ... SwE7JajaBy

Wow. Yeah I need smaller than that!

Coop

Hair pin cut at a 45 deg works perfect. Thanks to Monochrome.

Holy poop that worked great! Done. Gonna go see if that fixed my issue.


Coop

Went down to the car to plug everything back up...only to find I left the door open and my battery was dead. Doh.

Spent a good 30 mins on the charger and she fired up with both o2’s working!!!!!

Woooooooot!


Coop

Good work.

So I did this because it ran really rich, well that start up might have been more rich then when the ecu was messed up. Maybe it was from it not starting before and dumping fuel. But I sure hope I didn’t just make it worse at idle when I was trying to make it better.


Coop

Okay so I want to log my Wideband. Read up and it say, pin 55 for 91-93 cars.

You all have no idea how much I not only hate wiring but after this o2 shit I’m worried as can be.

Now pin 55 goes to fuel pump relay 2. It’s wires into a pin on my harness. What is fuel pump relay 2? Why couldn’t this just go to a blank spot?

Coop

I am so confused. So if I’m reading correctly I thought I would go into the 99 ecu harness side of things. But I think I’m suppose to pick the 92 car side of things. That’s the o2 sensor that I moved that started all of this crap.


Someone help me please.


Coop

[quote=""DCIV""]Okay so I want to log my Wideband. Read up and it say, pin 55 for 91-93 cars.

You all have no idea how much I not only hate wiring but after this o2 shit I’m worried as can be.

Now pin 55 goes to fuel pump relay 2. It’s wires into a pin on my harness. What is fuel pump relay 2? Why couldn’t this just go to a blank spot?

Coop[/quote]

Forget logging your wideband at this point. Get your car running right first. If I remember right there are other pins for 0-5V logging, and you shouldn't have to spice into a narrow band wire to log a wideband.

[quote=""DCIV""]I am so confused. So if I’m reading correctly I thought I would go into the 99 ecu harness side of things. But I think I’m suppose to pick the 92 car side of things. That’s the o2 sensor that I moved that started all of this crap.


Someone help me please.


Coop[/quote]

With the adapter harness, you need to make sure the O2 wires go from pins 55 and 56 to 72 and 71 respectively for front and rear.

So basically on the actual car wiring, the O2s should be in location 55 and 56 on the connector in the car. The wires that match up to those pins on harness need to go into pins 72 and 71 on the 99 side of the adapter harness.

Again, make sure you are looking at the back of the female connectors (where the wires go in) as this is how the diagrams are laid out.

If you're trying to use the wideband to replace a stock O2, then you connect the 0-1v wideband wire to pin 55 of your original 92 ECU connector.

If you just want to log it, that's different.

[quote=""DCIV""]Okay so I want to log my Wideband. Read up and it say, pin 55 for 91-93 cars.

You all have no idea how much I not only hate wiring but after this o2 shit I’m worried as can be.

Now pin 55 goes to fuel pump relay 2. It’s wires into a pin on my harness. What is fuel pump relay 2? Why couldn’t this just go to a blank spot?

Coop[/quote]

Pin 55 is fuel pump relay 2 on a 99 ECU, but its the front O2 on a 1G ECU.

Your adapter harness takes care of this...If you trace Pin 55 from the 99 ECU back through your adapter harness it will not go to Pin 55 on the car...