I replace number 4 cylinder coil sometime back pull the AC off to take it out in order for it to idle I had a different procedure for it to relearn it worked since in the icy went back so I replaced the whole unit and now I have done the three relearn in this manual and a couple other different ones I've reset the computer several times with scanner and manually and smoked the vacuum lines no leaks check engine light is on bank 1 sensor 1 Bank 2 sensor 1 sensors when you first start it it revs to 2000 -3,000 RPMs. The lowest I've got it to drop down is to about 15 to 17 hundred RPMs you don't have to give it any gas in order to run 40 to 45 miles an hour any help would be grateful

2002 QX4 four-wheel drive 3. 5 l replace the IAC have tried the three relearn procedures in this manual also resetting the computer manually and with scanner the three relearn have been done manually my scanner will not allow me to do them originally it surged from 2000 to 3000 RPMs I can get it to drop down to 1600 in that neighborhood surging a couple hundred RPMs any suggestions

I had a similar problem. In addition to changing the IAC, I clean my throttle body and adjusted the throttle body sensor. After that, I was consistently getting 1000 rpms, finally figured out to adjust the throttle body stopper screw (name).

While I was researching, several people had to change their ECU too. Luckily, I didn’t have to do that. The cause for this is because coolant leaks into the IAC solenoid and can short the ECU. So, it might be worthwhile to check the ECU too.