The Chevrolet HHR has a unique air filter setup that can be quite confusing. Because of the tight space in the engine bay, the HHR air filter is housed in a setup mounted above the engine. Rather than being able to simply unhook a clamp or two and replace the filter, you must remove the entire setup. It's not difficult or complicated; it's just different from most vehicles.
Turn your engine off and let it cool down for about 20 minutes.
Trace the air intake duct to the passenger side of the engine bay (near the washer fluid reservoir). Use your hands to unhook the hose.
Detach the mass air flow sensor from the main air tube (front of engine bay). Remove the hose clamp with a flat-head screwdriver to unhook the tube from the air cleaner assembly.
Grab both sides of the air cleaner assembly and lift it over the oil cap. Set the assembly upside down on a flat surface.
Remove the seven torx screws from the air cleaner assembly. Then separate the cover from the assembly to access the filter. Detach the old filter and discard.
Insert the new filter and replace the cover. Tighten the seven torx screws and mount the air cleaner assembly back on top of the engine.
Reconnect the air hose clamp, and tighten the screw to secure it. Reattach the mass air flow sensor connection. Insert the intake duct into its mounting position (near the washer fluid reservoir).
