I have a 2006 gmc envoy,check engine light keeps coming on,the code says it's a vacum leak,my ? is how common is this and where would i start?

GMC sent me a letter saying that gas guage not working has been a problem and they will fix and pay half.
Also my mechanic says that it is common to get a check engine lite when you add gas to tank, especially when you fill it. Sometimes I will take off gas cap and let air out then replace cap and the check engine lite will go off. (usually). Nothing to worry about.

Could be, although I'm not aware of a specific code that exists that says bad battery. Envoys and Trailblazers need a lot of juice and if the battery is starting to go, look for more codes and problems to pull up with that check engine light. Did they give you a specific code? When the check engine light comes on, it's telling you that there is a code stored and will point to the problem. Code will almost always start with PXXXX

If you don't have a code reader yourself, take it to a place like Autozone that will check it for free and give you a printout of the code. Let me know if you need more help.

Hello
Does the light ever come on while you are driving the vehicle? It is possible that the vehicle does not trigger the code on the key cycle when vehicle is connected to the OBDII scan tool (a cycle is the time from when a vehicle is started to the time the vehicle is turned off) you should however most of the time be able to check a vehicles trouble code history to see what may be turning the light on
Good luck
Chris

A check engine light can be any combination of about 300 codes. Some are simple, like a leaking fuel cap and some get very involved. Without the actual code(s) there is no telling why the light is on.

the idle is not adjustable on this vehicle, it's computer controlled.. sounds like a large vacume leak. open the hood and listen for a loud hissing noise.. check the pcv hose, they tend to come off.

There is a malfunction in the StabiliTrak system.
The only fix is to take it to the dealer. They will more than likely pull a diagnostic trouble code {DTC c0196} and reprogram the EBCM (Electronic Brake Control Module).

This is common problem with
2006-2007 Buick Rainier
2006-2009 Chevy Trailblazer
2006-2009 GMC Envoy
2006-2009 Saab 9- 7X
2006-2009 Isuzu Ascender

Diagnosing and reprogramming is a simple procedure, and most dealers won't charge you to do this service.

Best of luck!

Had the same prob. Mine was the O2 sensors..... I replaced Both and [knock on wood] have had no more probs.......

Service Engine Soon (SES) or Check Engine Light On, DTC P0480, P0526/P1481/P1484 Set (Replace Engine Cooling Fan Wiring Harness) #05-06-02-012B - (10/19/2006)

Models:2004-2006 Buick Rainier
2002-2006 Chevrolet TrailBlazer, TrailBlazer EXT
2002-2006 GMC Envoy, Envoy XL, 

Some customers may comment that the Service Engine Soon (SES) or Check Engine light is illuminated. This condition may be intermittent and upon investigation, the technician may find either DTC P0480, P0526, P1481 or P1484 set.

This condition may be caused by the cooling fan harness chaffing against the plastic guide it routes through. This contact may damage the insulation of the wires enclosed in that harness.

Replace the wire harness: 
Part Number 89024920 Description Harness Assembly, Engine Cooling Fan Wiring

Good luck and keep me posed. 

yes, good suspect.. but code check it for soft codes you may not be seeing a check engine light..also related are O2 sensor/computer itself/TPS/ oil pressure switch/ resistance to fuel pump after warm(failing) and some others.........good luck