New.help plz.exhaust/emissions problem

[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

 

[07burb]

Cutting the cat out is really up to your local laws. many states won't allow that come time for your vehicle safety and emissions testing. If it was me I'd just go ahead and replace the O2 sensor(s) and replace the cats at the same time you get dual exhaust put in

 

[99hoeZ71]

Thanx for advice.but where I'm from they don't make us do emission tests so it's not enforced.I'm also doing on a budget, was basically trying to see if I can kill 2 birds with 1 stone.does anybody know when they do a cat back exhaust system do they still use the#2 o2 sensors or remove/bypass them?

 

[lesterl]

They dont emissions test here either, but if you cut a cat out they will fail you for lack of emissions equipment.

That being said, why is the cat bad?

Dont just replace parts at random, do some testing to find out what is actually wrong or it will fail agian....

 

[99hoeZ71]

Who will fail me? I've never had any one of my vehicles tested for emissions. But thanx everyone, I went ahead and replaced o2 sensor.. light went off...putting magnaflo cat back exhaust system this week!! Thanx again everyone for the replies.

 

[lesterl]

Missouri will fail you on inspection if the cats are missing (they dont check that they work)....

 

[99hoeZ71]

No brotha, not here in Colorado.I'm thinking they might only in Denver tho? I live in pueblo maybe 100,000 people if that.lol