hhrfreek

Hey guys I have been researching compatible exhaust systems and I'm looking for a downpipe for my 2.4l. I have come across many cobalt pipes but none for the HHR. Would the Cobalt downpipe fit properly?

hhrfreek

It works. I installed the cobalt addiction header and zzperformance 3" downpipe(2.5" taper to stock exhaust) with high flow cat and they fit great. Took about 3 hours. Sounds awesome with the stock back exhaust. Performance wise I notice nothing in lower rpms but after 4k it pulls harder though I'm no human dyno. I noticed many people have stated the code 420 will come up when installing the new dp but after 20 miles all is well. I'll post again if I get a cel. I did buy the oxygen simulator from vibrant performance but it will not work because there is not enough room between the chassis and pipe so anyone doing this will have to resort to a 90 degree simulator or the 2.5" dp.

hhrfreek

I've put 1500 miles on the hhr since the header/dp install and no cels or other related issues.

1970judge

Link to the header you guys used?

Also, either of you have a sound clip of your current exhaust now?

hhrfreek

Hey haven't been on for a long time. I purchased the stainless header through http://www.cobalt-addiction.com/ but it appears their website is down or they are no longer in service. The header looks identical to the ones being sold at http://bad-mab.com/ecotecheader.htm You can pickem up on ebay for less than $200. Don't have a sound clip. I'm guessing you will notice more cabin noise but I put the header on at the same time as the larger downpipe.