Kenny quoted me $15 to weld in a bung before the cat

 

I believe anyone I've asked quoted me around $30, so thats damn good then.

 

I talked to Kenny and he said it shouldnt throw codes with the GM Stage 2 kit/reflash... I will be installing my xtc downpipe and header on jan 23rd

 

does anybody know what is the best set-up for headers and a downpipe....ie prices & gains??

 

without a cat looks like it will throw, i dont know about if it has one

 

has anybody heard anything about the zzp downpipe?

 

I thought the GMPP catback system came with a downpipe? Please bitch slap me if I am incorrect.

 

intense downpipes have no cat in them

 

wish you were closer

 

it does not, the gmpp exhaust is from the downpipe back

 

The 2.5" XTC downpipe w/cat will throw a p0420 (low cat efficiency) code on the 2.4, but not on the 2.0. The ECM is more sensitive to triggering this code on the 2.4, from what I understand. If it does pop a CEL, hp tuners can turn it off. There are other devices (both electrical and mechanical) available to avoid the code too.

This is one: http://www.o2sensorsimulator.com/?gc...FSREgQod5XiaLg

Here's another: http://cgi.ebay.com/ebaymotors/CHECK...67820810QQrdZ1

 

So the ZZP downpipe doesnt sound good??

 

Some of you might want to check out our myspace page... and look at our newest blog. Prices will be competitive so have no fears.

 

so why exactly is everyone saying to go with a downpipe with a cat? just for emissions reasons or is there some sort of performance advantage to having one as opposed to not

 

Ok. I see a lot of missing information when it comes to cats and no cats. First off, if you get a catless downpipe, Yes, you will get a code. Is it the end of the world? no. All it's saying is that that cat isn't working correctly. Well, it shouldn't be. You don't have one.

There are 3 codes related to the Cat. I don't have my list next to me right now, so I don't know which one's they are. I think they're something like P0038 and 39, and then another further down the list. Once again, I'm not sure on this, so don't sue me if I'm wrong.

::EDIT:: I've looked up the codes. They are
P0036
P0140
P0141::

If you get the Downpipe with cat, it shouldn't throw the code. A cat is only there for emission reasons. So if you live in a state where you have to get checked every year, don't go catless. If you live a great state like Michigan, where they don't test, go ahead and get catless.

What will happen to your supercharged car when you go catless? Well, there is one more thing blocking the exhaust. Due to this, you will see a decrease in BOOST. However, that doesn't matter, cause you still have the same amount of air going into the engine. It's just easier for it too leave as well. You will be making the same/more power with less boost. This is great for the 2.5 and 2.6 pulley, as it's less pressure on your engine.

Lets go back to the codes for a moment. One of the codes is for the Cat heater. The cat only works properly once it's heated up. If you disconnect the second 02 sensor like I have, you will get this code because it's not able to heat it up. Another code I believe is for the heater working as well, with the last one being for the cat working properly itself.

If anyone has any questions about cat-less, ask away. I have a video up on You tube before and after installing my cat-less downpipe.

Corsa Sport with cat

Carsa Sport without Cat

It's more noticeable in person then it is on video. Also, the surge you hear at idle was due to a bad injector, not the cat, so don't let that sway your opinion.

Once again, please correct anything if I'm wrong.

 

hmm.... what about hahn's downpipe? it comes with a cat

 

good info
one question though. i should probably install the full exhaust from headers to dp to catback then install my wideband so they can set up some sensors to get some readings, right? or it wouldnt make a difference now or after.

 

I'm kinda confused by what your saying. Are you asking if you should wait until you have a full exhaust to get an A/f gauge?

It doesn't matter when. I still have the stock header on. When you go to install a bung for the A/f gauge, it goes in the downpipe, so make sure you don't plan on changing this once you do it. The gauge I have, The AEM one, states in the instructions the range away from the header.

Anyway you go, if you plan on doing any tuning, get an A/F gauge. And please, make sure it's a wideband.

 

what are the advantages to no cat??????? cause I have the 2.5 free flow cat and dp I'm about to bolt on

 

Going catless is good for only 1-2hp, not worth it in my opinion, unless you're building a race car.

 

sorry i was jus a lil confused to as where the sensor goes but now i know its on the dp, THANKS.

 

Other then 1-2 hp, it's also good if you use leaded racing fuel while at the track. Lead can cause your cat to clog up quite quickly, and I think some other things as well. But I'm pretty sure that my track you can get 100 octane unleaded. I think it's 104 and 112 (?) thats leaded. I might be pulling these numbers out of my ass. I've only used 100 so far.