PLEASE PLEASE PLEASE help!!!. I have a 2005 chevy equinox LS with 99,000 miles on it. I’m having high idle/shaking when the car is in drive but stopped (at a light for example). I’ve had replaced the Throttle Body, EGR Valve, Motor Mount, 02 Oxygen sensor (upstream), Tune up, and spark plugs replaced twice. There are no lights on the dash to indicate a problem.. I’m at a loss as to what could be the problem now… PLEASE PLEASE PLEASE help me find the issue

 

Remove the engine cover and make sure the nipple that screws into the upper intake for the brake booster hose is not damaged and is properly tightened.

Does it idle high in park or neutral without applying the brakes?

Also, when the EGR valve was replaced, did they install the newer design EGR valve? If so, was the PCM recalibrated?

 

Had a similar problem that was corrected with new spark plug wires.

 

It actually Idles both ways. At first it was just when in drive applying the breaks. Now it also does it in park. Also the EGR Valve was replaced with the newer one. I had to replace the entire EGR Valve including the hose because of the new design.

 

It actually Idles both ways. At first it was just when in drive applying the breaks. Now it also does it in park. Also the EGR Valve was replaced with the newer one. I had to replace the entire EGR Valve including the hose because of the new design.

 

Its you brake booster, the seal must be broken. Try this, using some vise grips, cut off the passage to the brake booster, just attach them to the hose leading to the brake booster ( make sure there on there tight enough to not let any vacuum get through, then turn the car on, if the idle goes down to normal, just replace the brake booster.