Changed battery in 02 envoy, now does not idle right

Because it is a 2002.
Because it is a GMC.
Because it is an Envoy.

Go to Scotty Kilmer's YouTube page and type in GMC Envoy.

You need a good auto-electrician with a high end scan tool.

You could try disconnecting the battery for an hour in the hope of resetting the ECM and all the Body Control Modules. Make sure you have your key in the ignition when you reconnect. Wait 15 minutes. Make sure you know the radio code. Make sure you are ready for surprises.

Unplug 02 sensor and rap it up so bang around then take it for drive

You need to have the throttle body cleaned, make sure both the front side and rear side are cleaned thoroughly. Changing the battery reset the computer to factory default settings which are different than when it operated with a dirty throttle body.

WHEN EVER YOU DISCONNECT THE BATTERY.THE PCM WILL LOSE IT MEMORY PCM HAS TO RELEARN IDLE POSITION.SOME TIMES DRIVE AROUND BLOCK FEW TIMES CAR WILL RELEARN TO IDLE.IF NOT GO TO DEALERSHIP.THEY WILL RESET IDLE.USING A T ECH 2 SCANNER.THEY PROBABLY CHARGE YOU $35.00 OR LITTLE MORE.

Engine temp too low is usually the thermostat, was this replaced too? If not, replace it. Might check out the fan clutch and the engine coolant temperature sensor.

As far as the vibration, have you taken a look at your tranny mounts? Usually vibrating in gear while stopped is the engine mounts, but I've seen the tranny mounts cause this too.

Also, check out the upstream 02 sensor and make sure it's operating correctly. Have you changed your fuel filter?

Also, just making sure.....You did have the battery disconnected while cleaning the throttle body right? If not, just unhook it again for a minimum of 30 minutes. After that drive around for 20 minutes to reset the computer.

While several mechanics couldn't find anything by using their computers, some of these will not throw codes if they are just about ready to fail.

Anyway, some things to double check here. Hope at least some of this helps, because it sounds like you're doing the right things.

There are a few things that you can do, do get it idling correctly, and it's fairly inexpensive.

1. Clean your throttle body with throttle body cleaner, with the battery disconnected. Needs to be shiny. When finished, drive around for 20 minutes or so with all accessories turned off, so the computer can relearn the newly cleaned TB. About $7 for the cleaner

2. Replace your spark plugs with A/C Delco 41-103, will idle better with this plug. Around $7 ea
3. Replace your upstream 02 sensor, the one right after the exhaust comes out of the engine, easy to replace. Between $67 and $80, try to stay away from Bosch.
4. Replace your fuel filter around $15 or less.
5. Check your vaccum lines for leaks.

I take it you have the I6 engine? Use AC Delco 41-103's for the spark plugs, these engines love these plugs. Other brands MAY cause the engine not to idle nice and smooth. Clean your throttle body with throttle body cleaner, with the battery disconnected, needs to be nice and shiny. Change the 02 sensor upstream right next to the exhaust manifold, that's the easy one to change. Also, replace the fuel filter and air filter. And of course, change your oil, Mobil 1 synthetic is the best for these. Check all your fluids also, like differential, tranny, xfer case and so on. If you do change the fluid in your tranny, use GM's new Dextron 6, will shift better and make your transmission last longer.

Sounds like you may have disconnected the battery. Does the rough idle only happen when the defroster or A/C is on? If so clean your throttle body with throttle body cleaner with the battery disconnected. When finished, drive it for 5 or so miles with the defroster / AC off to let the computer relearn the settings. This will solve your problem.

did you check to see if its the right amperage to power your vehicle?

Cleaning of the throttle body is in order, grime build up is preventing throttle plate from closing completely at idle.