Vacuum Line For Vents

[BigMikeO]

So, i think a vacuum leak in my vent system is throwing the SES light for "Catalyst efficiency low-bank 2"

 

one of the possible causes for this code shows Large Vacuum leak. It had been on for about two weeks, i have only had it for 2 1/2 weeks. Typically i always have the Vents on because I like to feel air movement. The vents have always given me problems with switching to different settings. So I just turned it off one morning and opened the windows. The SES light turned off about half way to work so about 15 minutes. It stayed off for 3 days. eventually it got cold so I turned the vents back on and switched to face and the SES light turned on again after about 15 minutes. So I'm thinking there is a vacuum leak that is causing the switching problem and also throwing the error about the CAT.

 

Thoughts?

 

Where is the Vac line that I should be looking for? is it behind the dash or in the engine compartment?

 

Not sure if this is in my signature or stats but I have a 1999 K1500 Suburban with a 5.7L

 

Thanks

[redvett]

Your HVAC system is all electronic an has no connection to the PCM. You probably will need to replace the Cat for the P0430 and then resolve the HVAC actuator or controller problem.