Harness Plug question

[Luni]

I have just got done swapping motors in a 2001 MP3 to a 2002 ES motor (same engine of course). I basically swapped everything over to the other longblock, so all sensors, all necks, all housings and manifolds are native to this car.

I have this extra harness plug that goes on the run of the harness that connects to the front of the motor at the coolant neck. There are about 3 sensors that I found to plug in, and they all work fine, but I have an extra not used plug.

I have let the engine warm up, and it is not pulling any codes, and it runs awesome, everything seems fine, no CEL, blah blah blah

Just wondering if Im dumb and overlooked something, or if we all have a spare harness plug on the MP3/MSP harness (im thinking the 2 cars have the same harness, and the MSP might have a special sensor relating to the boost systerm or something the MP3 doesnt have.

Anyway, I can take a picture of the coolant neck area where I have the extra plug for reference if needed.

Thanks in advance.

Robert

 

[Luni]

Nobody?

I know on an MP3 or a MSP it might be a bit tricky to see with the plastic engine cover on, but on a standard protege ES 2.0 it would be right there.

 

[xelderx]

Pictures! Sounds like it's possibly an O2 sensor harness.

 

[xelderx]

Wait....is it the harness that is on the driver's side of the head? Where the water temp sensor is?

 

[Luni]

Well yes, its RIGHT there on that chain of harness plugs.

However it doesnt go to the water temp sensor, I got EVERYTHING over there plugged in.

It isnt an O2 sensor wire, theyre both plugged in.

It isnt a tranny wire, theyre all plugged in (theres 2 I believe)

It doesnt go to the throttle body cause it doesnt reach, it cant go to the intake manifold or any of the stuff up there cause it doesnt reach, and it cant go to the airbox cause theres nowhere in the airbox for it to be.

Im baffled.

 

[Luni]

We figured it out. The bracket on the drivers side of the engine that we had completely was missing a sensor.

It appears to be some sort of ambient air temprature sensor, possibly for the radiator fans or something. Dunno. It doesnt CONNECT to anything, it just sits on the bracket, and plugs into the harness. It reminds me of the sensor I have in my engine bay for my intercooler fan in my MR2.

Anyway, all is figured out, disregard cry for help in this thread.

 

[Prodigy]

Is it that small black plastic piece?

It should go in the intake.... but I have mine mounted to the body of the car. (perfect hole for the grommet below the coolant overflow bottle)

 

[TheMAN]

this?

 

[Luni]

Yeah man, Thats it.

What does it do?