i picked up a header or ex.mani from a 2007 ss/sc cobalt (manual) ..wondering if it will fit on a 2008 HHR 2.2L (auto) ??
thx

 

Yes it's an exact swap. The downpipe is the one that's different between auto/manual. Just don't tighten the bolts too much on the head or the thread will strip.

 

Okay cool, I was told that it would only fit if my car was manual as well ..I know this header has the o2 sensor on it whereas the autos have it on the pipe..it's okay if I just plug it?
How tight shud the bolts be tightened?

 

Yeah you'll be fine plugging it. I know a couple people who use that hole and plug the one on the pipe. You could go either way. Honestly I'd use the hole in the manifold. The torque for the manifold bolts is 106 INCH-LBS. NOT foot-pounds, but inch.