99hoeZ71

Thank god for this forum.Help plz.heres the problem...on my 99 Tahoe 5.7L the check engine light would go on and off, now it's stays on.codes I get from advanced are P0141( oxygen sensor #2 bank 1), P0171 (fuel trim system lean bank 1), P0420( catalyst system low efficiency bank 1).so I was thinking the problem is the o2 sensor ($55)or cat ($225)?Another question I have is I'm also wanting duel exhaust($300) so I'm wondering if I get the exhaust done is there a way to maybe just cut the cats out to eliminate replacing the bank 1cat and/or o2 sensor?I just want the annoying light off if there's any way to bypass by putting duels.Anything will help thanx

Thank god for this forum.Help plz.heres the problem...on my 99 Tahoe 5.7L the check engine light would go on and off, now it's stays on.codes I get from advanced are P0141( oxygen sensor #2 bank 1), P0171 (fuel trim system lean bank 1), P0420( catalyst system low efficiency bank 1).so I was thinking the problem is the o2 sensor ($55)or cat ($225)?Another question I have is I'm also wanting duel exhaust($300) so I'm wondering if I get the exhaust done is there a way to maybe just cut the cats out to eliminate replacing the bank 1cat and/or o2 sensor?I just want the annoying light off if there's any way to bypass by putting duels.Anything will help thanx