Originally Posted by hhr06NJ

the idling problem could be a dirty / sticky throttle body. gently clean it with engine off using carb cleaner or throttle body spray cleaner. put a rag inside the throttle body so no cleaner gets down into the engine.
WRONG!! Use Throttle body cleaner only!!! Some have used carb cleaner without problems, but it sure isn't recommended. Stuffing a rag inside the throttle body is not good - care must be used when moving the throttle plate as several people have damaged theirs. https://www.chevyhhr.net/forums/gene...y-20839/page2/

the intimidating air cleaner lifts straight up - no bolts. WRONG!! That will definitely cause damage - tools are needed. If you can replace yours by just lifting it up, then you are missing some parts. Best to read how to do it correctly: https://www.chevyhhr.net/forums/main...-filter-10757/

 

I think he meant the "housing", not the "filter". Both taken together = air cleaner assembly.

There are now products labelled "carb & throttle body" cleaner. Main things to avoid are MEK and silicone, MEK dissolves plastic and silicon kills catalytic converters. I would not worry about getting any into the engine as it evaporates in seconds.