Hey everyone just wanting some input on which downpipe to go with.
I've currently got the injen CAI and aftermarket muffler. I do not plan to get anything major for the car in the future. Just want something a little more "open".

Its between the 2.5 with the high flow cat or the 3.0 with the high flow cat. I read the 2.5 was good on the SS/NA but just wanted other's opinion.

Thanks!

 

2.5 is best thing for your car. You wont need 3 inch unless youre supercharging or turbocharging

 

That's what I figured but just wanted to make sure. I thought about turbo'ing in the future but felt like I wasn't gonna spend that much $$ on the cobalt. thanks

 

a 3 inch with your existing mods will just reduce power and make it louder, you only see gains with a 3 inch on a le5 if you go supercharged above 250-300 WHP, or if you go turbo. needs backpressure for NA

 

i dont think it has to be that high to see gains...I saw gains from adding a 3 inch to my setup and I dont think im at 250 whp

 

2.5 you'll be happy

 

He is NA. 2.5 is all he needs

 

i know i had said that already. was just telling Ceeker that i saw gains from a 3inch dp and im not at 250whp

 

Did you dyno it before/after? I'll bet you lost mid-range torque

 

no havent dynod my car yet. was just guessing i gained some power from it since it spins out alot more now with it

 

2.5 is good enough for S/C too

 

Yes.

It sure is.

 

it is lol. didnt say it wasnt just said i got the 3inch and im happy w/ it

 

That's all that matters man.

 

So you had a 2.5" catted zzp dp on your car, then switched to a 3" catted zzp dp, all while keeping the same mods on rest of your car?

 

if you replace your downpipe will the car throw any codes?

with a zzp down pipe that is

 

Yep, p0420 iirc, cat efficiency. Got it with mine, as most ppl do.

 

This will solve your problem:
Exhaust - Vibrant Oxygen Sensor Defouler

Spaces the rear o2 sensor from the stream, eliminates the code.

 

^^ works sometimes, sometimes not.

 

NA = 2.5" dp. Nothing bigger on the exhaust system. As stated before NA cars rely on backpressure. Removing that will more than likely kill hp imo. Turbocharged cars, however, love an open free flowing 3" exhaust. I sure know I do lol.

 

i got a P0420 code with my 2.5" hi-flow catted ZZP DP. trifecta tune can fix that easily!

 

Tune will get rid of the code, but will not ready the system monitor, if anyone is concerned with that for inspection.

 

I've seen it on over 25 cobalts and it has worked on every one.

 

As long as they all bought that exact defouler, I can see it. Just that some others will not move the sensor out enough to have an effect. 25 balts eh...that's alot of modded balts to personally get under and check out their piping...internetz reading no countz

 

where do i get this trifica tune? how does it work? is that when you go to a shop and they hook up your car to a computer and "tune" it?