This is rant for the AIV, piece of crap rust factory.
http://www.nissanpathfinders.net/forum/index.php?showtopic=19382
Ive dealt with that rotted AIV box. About a week ago I took it and the AIV case out of the damn engine bay. The AIV box was rotted completely, just mushy rust that reeked of exhaust odors. The AIV case was calcified, but I might try to salvage it. The rust is bad, its a shame I have no camera, youd be surprised at the gap over the wheel. MY1PATH is lucky he doesnt have my rust damage, hehe.
I take it for a spin and notice the car makes a lot of more noise. I come back and play with the throttle under the cleaner, all that noise comes from that pipe. I also noticed moisture, so I freaked out and grabbed some WD40. I used up half of a full can, drenched the area it sprayed. It wasnt bad, but cmon, exhaust gasses had eaten the AIV box. I couldnt take any chances with rust. I stuffed a rag into the pipe and wrapped it a piece of cloth, then secured it all with a zip tie. The pipe coming from the intake to the aiv case I also plugged. Whats the point? Id be losing air?
Now Im wondering about the vacuum line that was connected to the aiv solenoid. I forgot when it was was open or capped, but the engine would take noticably longer to decelerate back to idle before I would shift to another gear. This is after i removed the box, case, and solenoid.
I noticed the car runs better, a bit stronger. Gas mileage took a drop, a bit too much. Engine sounds different too. Instead of having two alternating sounds from the exhaust, there would be one larger sound. After reading the service manual, Ive come the conclusion that the ECU is running the engine in "heavy load or high speed mode" or some such. Normally the injectors should be runing alternating, instead its both at the same time. No codes displayed from ECU in Mode 3 or 5, btw. Ill have to learn how to read Mode 1 and 2.
All this time I thought the AIV crap brought exhaust into the engine to reburn it. Now I dont have a clue. Im going to check all sensors, clean the TBI, MAF, and hell knows what else. Im gonna mess with the wiring for the aiv solenoid plug. Gonna solder a 35 ohm reisitor to it, maybe it will fool the ECU? Theres a diode in the plug that mustve blown, so I dunno about that.
Yeah I know long rant.