what are some good aftermarket parts to add onto my truck for both mpg and hp.

K&N filter - i notice no one has said anything about this. Does anyone have this intake?

are there any exhaust systems (preferably cat-back system)

And i heard about the hhr radiator fan, is there a write up on this?

Thank you, Chad

 

K&n is a great way to go, got one my self. Love it by the way. Exhaust yes, and performance chips yes, throttle boby spacers. Lots to do if you have the money.

 

Your minutes with the 3.7. Evan, cai and catback will do the most...don't know much about the chip.

 

Chips are crap IMO save your money!

 

Here's my thread on installing the HHR fan and SPAL controller.

https://dodgeforum.com/forum/3rd-gen...-tutorial.html