What is wrong with my cobalt?
I recently bought a 2006 Cobalt SS SC stage 2 w/ 126K and a rebuilt top end. It started hard due to a weak battery with corroded terminals so I replaced it. After that, it hasn't run the same. It's got a rough, surging idle and stalls out after a minute or so of running. It would also go into limp mode when my RPM's went too high. I tried cleaning the TB and making sure all vacuum lines were in place, but that didnt help. It also smoked a lot. i ended up replacing the engine when I found some internal damage in cylinder 1. Now it runs a little longer and doesn't smoke as much, but it still stalls and runs rough. I can't take it anywhere - I can't really get it into reverse and it stalls when i give it gas in gear. The most frustrating part about this is that it's not throwing any codes. I work at a garage and have run out of ideas on what could be the problem. Please help.