AldenSS

2000 ss camaro with 100k. bbk throttlebody, slp intake, slp MAF, slp cat bac exhaust. codes just came on the other day, car has been stalling out when cold on start up, and a loud whisle noise from throttle body area when cold for a months now. idle is normal cant find an air leak so far at all, and no exhaust leaks, and fuel pressure normal. car runs fine no lose of power. im going crazy trying to figure out wats going on seems like a vacume leak but with no high idle. i just ordered a new bbk ssi intake manifold and hoping ther is a leak from my stock intake manifold gasket. is it possible the cat code p0420 has somethign 2 do with lean codes? lean mix giving downstream o2s a wrong cat reading? or maybe at 100k one of the original cats is just bad and the lean codes rnt related.