tamadrummer

I'm contemplating picking up a catless downpipe for my next mod, but I have a few questions first: 1. Is it worth it for $140? 2. ZZP says that the slanted o2 opening won't set off a CEL for the cat, but I find that a little hard to believe. Does anybody make an o2 simulator that can be used to eliminate that o2 sensor? I used one of those on my 98 Tahoe a few years ago and it worked just fine, but that o2 sensor was further down the exhaust system.

Thanks!

hawkssoccer11

iTrader: (13)

get the catless dp. it opens up so much power! and yes the slanted 02 bung wont set the CEL off at all. i have a turbo xs dp with a similar set up and i have never thrown a CEL for the DP since i bought 3.5 years ago

Snail_SS

iTrader: (3)

Yup that ^ and the code doesnt set off because the with the bung it takes it away from the exhaust gases so it reads less flow so it thinks its on correcr numbers

tamadrummer

Alright, cool! Is it pretty easy to install? I haven't touched the exhaust on this car, other than muffler delete.

hawkssoccer11

iTrader: (13)

its not too bad to do. the hardest part is trying to figure how many extensions or beers your gonna go through the get the top bolt off because its so close to the frame and its just a pain to get off sometimes haha

Snail_SS

iTrader: (3)

Yeah its pretty simple its what 7 bolts if i remember correctly and the o2 sensor. make sure you put some wd40 or something like that a day before your going to do it to loosen everything up

ECaulk

iTrader: (6)

If you want a cat'd DP and you'll be near Denver anytime soon I just switched to a cat-less and have a cat'd to sell. I have to put the stocker on for emissions since they rejected the hi-flow cats even though it passed the sniffer. Not sure of the power difference but it does spool a little faster with the cat-less

tamadrummer

Nah. I think I'll go catless. Are the gaskets reusable or do I need those too?

tamadrummer

This might be a stupid question...but, if I wanted to run the downpipe that doesn't have the place for the o2 sensor, what would I need to do? Does anyone make an o2 sensor simulator or would that code need to just be disabled?

Just trying to look at my options.

ECaulk

iTrader: (6)

Depends how careful you are removing things, the one that might need replaced is between the exhaust and the dp.

Not sure how you would run that, I just switched the code to set but not illuminate

tamadrummer

Does that o2 sensor affect how the engine runs at all? Also, how did you disable the code from illuminating? I'm assuming it's a special scan tool? Or will the trifecta software I got with my tune give me the option? I only ask because saving $40 on the downpipe would be nice lol.

ECaulk

iTrader: (6)

Hptuners is how I did it. Not sure on how it effects the engine running I never noticed an issue when it was in the angled o2 bung. Right now I have the cat efficiency code off but the o2 sensor installed in the gas stream.

tamadrummer

Alright. So is the general consensus that the angled o2 bung is the best way to go? It's $40 more -_-
how much does hptuners charge for something like that?

tamadrummer

Actually, I just saw that badnewsracing has them with gaskets and the o2 fitting for $135!

Olybaltss

HP Tuners is the tuning software that would be used, so if you had the software it would cost you nothing. If you need to buy credits to unlock your particular model year it's $100 i think.

chris88z24

You'll most likely lose power with a catless downpipe. High flow is the way to go.

ForceFedDork

Really chris88z24, really, are u really sure a catless will lose power over a high flow cat? Are u certain of it? U got a couple of dyno sheets that can support that statement? A back to back comparison with just that 1 change?
If u don't, I think it might be best if u don't make statements that dont make logical sense and don't have data to back it up.

CobaltSS 16

iTrader: (3)

definitely go catless. best thing I ever did to my LSJ.

LNFs are the same way.

and chris is wrong - check out the dyno thread... it'll give you a good idea of what people are making based on their mods.

bmartz1991

iTrader: (35)

The cat is the most restrictive part on the car, going catless is a must.

chris88z24

Catless is good if you want your car to both sound and smell like ****. You will NOT make more power over a high-flow setup. There are 700hp factory cars that have cats, your ******* Chevy Cobalt is not going to benefit from not having one. I've had so many different exhaust setups over the years that I'm not even going to bother arguing any further with you noobs.

HOWEVER, if you do insist on not listening and going Catless on an LSJ car, I HIGHLY RECOMMEND you use some sort of silencer in the exhaust to combat rasp.

chris88z24

Really, ForceFedDummy. You've been on this forum for less than two years. I don't need to post a ******* dyno sheet to prove a point. I have experience pal, 8 years of messing with these cars in particular. If Catless was better i would have my car setup that way, lol. And so would Staged07SS, even though he doesn't drive his car very much...

bmartz1991

iTrader: (35)

Popcorn

murlin15

Isn't this the lnf section??? And lnfs sound great with a muffler delete and catless down pipe

Snail_SS

iTrader: (3)

To what i was told gains from going from high flow to catless are minimal you wouldnt even notice them

footballplaya3k

iTrader: (1)

You sure you have experience? Because you sound quite retarded saying catted makes more power.