Finally got my car started back up after its been sitting for like 6 months. It started up great but there is a pretty loud popping coming from the exhaust. I'm trying to get my car smogged out here in CA so I had to put all the emissions stuff back on. I put a new egr valve back on, smog pump(used), magnaflow catted x-pipe(used), and new BBK headers. The check engine light isn't on. I tried to take it for a drive but it was pretty loud with all the popping, which i'm assuming is a backfire right? Also on my short drive it didn't seem like it had very much power. Any help would be great.