So the P0506 code came back on my 2007 GMC Envoy. I went through the steps in this post, but I am still getting the error. After doing some research it seems that it is time to pull the throttle body off the intake manifold and clean it thoroughly!
To perform this operation you will need some Throttle Body Cleaner.
And a rag!
The first order of business is to remove the negative cable from the battery. This is necessary because you will want the computer to relearn the positions of the throttle body when you are done cleaning it. If you keep the battery disconnected while you are performing the cleaning, the computer will reset and will be forced to relearn the positions of the clean throttle body.
Next you will loosen the two intake hoses from the giant plastic intake section on top of the motor. Then you can remove that giant plastic piece by taking the two 10MM bolts out that hold it in place.
Then you can disconnect the electrical throttle control connection from the throttle body.
Disconnect The Throttle Control Connector
Disconnect the vacuum line that is attached to the throttle body.
You will then have to remove the 4 10MM bolts that are holding the throttle body to the intake manifold.
Remove those bolts and take the throttle body off the vehicle for cleaning. I noticed that the front of the throttle body was very clean from previous cleanings that I had done but the back side was completely black and caked up with gunk. I sprayed the back side of the throttle body thoroughly, which removed some of the residue, and used a rag to completely remove all the carbon residue that was on the back side of the throttle body. I made sure that the unit looked brand new before reinstalling the unit back on the vehicle.
Clean Back Side
Clean Front Side
Re-installation is the exact reverse of the removal. Using the original gasket is fine as long as it is not damaged in any way. A damaged gasket may cause a vacuum leak and other unwanted issues.
After putting the clean throttle body in place and reconnecting all of the removed parts, I got the truck started and immediately noticed a difference. Idle was much higher and the throttle seems to be much more responsive. This helped so much the I think I will add a throttle body cleaning to the 50,000 mile maintenance schedule for this vehicle. I hope that gas mileage will also be increased, but we’ll have to see on that one.