have had this for awhile, doesnt affect performance at all and no CEL's. just during warm up, with car in neutral(5-speed), the idle hunts up/down, probably less than 50 rpm's. after a inute of so, flatens out to normal idle speed. has abl=out 130K on it and it runs great.....anyone ever hear of such a thing..??..HHR is an LT model with a 5-speed stick.

 

 

this is what i use.....may be time to do it again..
https://www.crcindustries.com/produc...-oz-05078.html

 

 

thanks, Oldblue....i've got both and will use correctly....thanks, again.