smog
Burning Brakes
Joined: May 2013
Posts: 789
Likes: 129
From: Los Banos CA
When I smogged my 79 last year, the shop told me that I needed the Y-pipe and single cat. They said the EGR valve needed a certain amount of back-pressure to operate properly, and it wasn't getting it with the dual exhaust that the car had when I bought it. When I removed the duals and put the stock exhaust on, I noticed that the previous owner had also hollowed out the dual cats, so that might have explained some of the back-pressure issue too. (I don't think the previous owner had ever smogged it that way, as the car had been on non-op status since 2001).
My 79 came with federal emissions (no air pump), so I didn't have to worry about that.
My 79 came with federal emissions (no air pump), so I didn't have to worry about that.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Good tips. Your cats as dawson said being CARB approved make sure they are "CA" cats. They got a stamping on them same thing just more money. Just went through this with my DD.
