WTF... my buddies Trans Am was just in for warrantied Cat. replacement... well they replaced the Bank 1 cat. and rear O2. two days later (today) the SES light came on again. They scanned it and said that bank 1 O2-1 is reading -3, bank 1 02-2 reads 0. Bank 2 02-1 reads -2 and the rear O2 reads 0. they said the A/F ratio was really lean @ 14:1. What the hell is up with that... why didnt they replace the Bank 1 front O2 as well, and why is my engine running lean just after the cat. replaced, never ran lean before???????

Help please

 

anyone??? please help...

 

could this be caused by the fact that i hear a sound from where they put the new cat..possibly that it wasnt welded right, or they missed a spot and there is a hole?????