ok just got back from the shop b/c....my check engine light came on due to got an header and downpipe with cat installed. They ran a diagnostics test and 3 codes came up. here are the codes P0420( cat efficiency below thershold).. P0171 ( system too lean)..P0300 Random multiple misfire..The mechanice at shop thinks that it could be a bad cat...b/c i got the 1/3/4 midleanth header and a 3inch downpipe with 2.5 exit from ZZP...it was recommended from couple of guys on the site b/c im supercharging it soon...so he also thinks that i might need a tune/reflash cause its a newer model...so what u guys think??

 

Between my header/downpipe and my intake I have 5 PCM codes thrown if that makes you feel any better, lol. You could say I need tuning pretty badly......

 

Is this the zzp mid and down Iwas thinking the same set up.hope everything is soon fixed up and running well.Keep us posted.

 

Why did you get a 3in down pipe with a 2.5 exit????

 

yea, that pretty much defeats the point. should have kept it all one size, 2.5"

 

Exactly. That makes NO sense...I don't even know why they offer it. +REP

 

Haha I've said that a million times about how pointless a 3" downpipe w/ a 2.5" exit is on countless header/downpipe threads and no one ever acknoledges what I say!

 

dats what the guys recommended on the site..im gonna be boosting in the futre..so dats what tjhey told me to get

 

So if I told you to spray paint your rims pink would you do it?

 

no...but they said i should be fine with that...

 

I wouldn't have gotten a cat either if you went out of your way to spend the money on a dp

 

well, codes aside, a good exhaust will be free of turbulence and will create a nice exhaust flow. by going from a 3 to a 2.5 it will be creating turbulence, not getting rid of it. that's why i said that it doesn't make sense. keep it all the same size next time.

as far as the codes, the lean code is nothing, loads of people get that. the cat efficiencey MAY be because the high flow cat is registering much more air than what it's programmed for stock. the other code could be nothing as well. if you haven't, delete the codes and see if it comes back.

 

You got really bad advice dude

 

think of it like this. the stock exhaust is 2.5 ", but then bottle necks down to like 2 1/4 over the axle. that causes restriction, and that's why you change out the stock exhaust to one that is all the same size, which ='s better flow. so you basically paid for that same restriction, just a half inch bigger. will it flow better than stock? sure. will it flow better than the same exhaust that was all the same size? no.

it's not the end of the world, just use it as a learning experience. don't feel bad about it either, if everyone knew everything about the cobalt there wouldn't need to be all these forums.

 

thanks bro..yea i he got the engine off....what bout a tune? should i need it?

engine light*

 

you shouldn't need a tune. is the light still on? that means they didn't delete the codes. try deleting them and see what happens. you can also disconnect the negative side of the battery for a few minutes, which will reset everything, and it may re-learn for the new air flow.

 

when i left the engine light is not on anymore...does dat mean he deleted the codes?

 

Yeah the codes are gone

 

thanks guys next time i do advice i make a thread or sumthing

 

GOOD idea...

 

can i get a tune now....and when i have my s/c installed would i need an another tune...im new to this tuning thing

 

you don't need a tune with just an exhaust. wait till you get the super.

 

You need a tune everytime you do something major to your car. I.E. different fuel injectors, very small pulley, etc. If you're putting on the SC just wait to do a tune unless you're going to be driving it around a lot. I've seen a lot of guys **** up their cars without having a proper tune.

With just exhaust you don't need a tune...

 

i got the ss/sc injectors too

 

Ok well your car doesn't KNOW that you have those injectors in. It needs to programmed/tuned in order to utilize them.