I thought they're all the same

 

iirc, the 99's have a lot a stuff different (numerous ac related stuff, abs sensors, steering rack & etc).

 

Probably emissions related..

 

Yes they are slightly different. I would know having a 99 and spending some time in the JY's going through other year maximas...

 

So it won't work/fit?

 

It will still work. Any would work. I think Nissan changed company from where
they got their parts or something but that is not going t o affect functionality.

Here is a good comparison
http://cdn1.autopartsnetwork.com/ima...1724454OEA.JPG
vs

http://i.ebayimg.com/t/95-96-97-98-99-NISSAN-MAXIMA-I30-IDLE-AIR-CONTROL-VALVE-SENSOR-/19/!ByQiSiQCWk~$%28KGrHqJ,!i!Ew5FV5-9dBMQ689uHq!~~_35.JPG

They look different but function the same...

 

I found out the 99 only have 2 plugs vs 95-98 have 3 plugs. It wouldn't work

 

actually if youd like to be technical...it depends on what your manufacture date is for your 99... some came with the same iacv as the 2000...mounted under throttlebody..some have the triangle looking iacv...i also have a 99 se-l and mine was originally mounted under the tb.....since the previous owner swapped motor and installed mevi i now have the triangle looking one...for now....dek swap in the works...

 

The rear answer is simple. 99s have a plug where the purple fast idle solenoid is supposed to be installed. It can be swapped over.

http://forums.maxima.org/4th-generat...-gen-iacv.html

 

Yup that's the one I have, why did they make it harder by moving the fast solenoid out of the whole assembly?

 

Perhaps they combined the A/C and power steering solenoids into one? You can still use the older style without issue.