Thus demonstrating exactly my theory that no two HHR's are ever alike, and if GM discovered a "matched set" coming off the line, they crushed one of 'em.

Kidding aside, vehicles are like people, utterly individual and unique despite being mass produced.

 

Strange thing: last week I installed a new exhaust header gasket and cat pipe; this week I decided to re check my torquing. I had to loosen all of the header nuts (they only get 10 ft-lb) and severely tighten the flange connection (I had to use bolts because the studs ...).

The first thing I noticed on the test drive was a huge increase in throttle response right out of the driveway!