Main Cat/Test Pipe Question

[Bimmer2Audi]

I'll be doing piggies within the next two weeks, and because I live in a small redneck town, I'd like to gut the Main Cats as well. What is the best way to eliminate the Main Cats? Test Pipes? Who offers just test pipes? How have you done it?

[The_Jerbel]

Get a length of pipe from a muffler shop and weld it in place of the CATS.

[Jsmooth65]

I envy you. Reminds me of my 1965 Mustang I built. I had 3" exhaust off the headers of my 351W stroker, H-Piped and back into two FlowMaster Deltaflow mufflers. Sounded like pure masculinity.

[Das General]

Cut the cat out and weld in a straight pipe...thats what I got.

[Jung]

hack out the cats, weld up new pipes.

[AudiSportB5S4]

yeah just cut it out completely and weld in pipes. ill snap a shot of mine in like 10 minutes lol

[AudiSportB5S4]

[Bimmer2Audi]

Thanks, does anyone know the length of the 2 new pipes that you used by chance? Any do the VAST 02 Eliminators have to be welded into these new pipes? I don't fully understand these 02 Eliminators...

[StuntManMike]

for those of you who welded in pipe in place of the cat what did you do for cel?

[AudiSportB5S4]

tricky tricky lol

[Bimmer2Audi]

tricky tricky lol

I'm also a DMC fan, but you didn't answer the question

[AudiSportB5S4]

LOL, if you are budds/chums/friends/lovers with your tuners they can code out the rear o2 sensors to not read

[lsc2g]

i plan on doing the same deal soon.. do you have the shop put in a spot for the rear O2 sensor and plug it back in with the CEL eliminator

or i guess have your chip maker give you the software for test pipes.. i think i'll have mine done and try the CEL elims first before giving APR a call

good subject!

[lsc2g]

how big of pipe should be used? i guess the muffler shop who does the job could figure it out..

[Bimmer2Audi]

i plan on doing the same deal soon.. do you have the shop put in a spot for the rear O2 sensor and plug it back in with the CEL eliminator

or i guess have your chip maker give you the software for test pipes.. i think i'll have mine done and try the CEL elims first before giving APR a call

good subject!

Bump the top question. I've searched the subject and there is really no info or threads on what you actually do with the Vast sensors.

[lsc2g]

i beleive you screw your O2 sensors into those things and they are basically spacers and then that is all screwed into the O2 spot.. this way the sensor sits up higher and gets a lesser reading.. or so is my understanding of this all..

[Bimmer2Audi]

http://vastperformance.com/shop/prod...products_id=68

Okay, so if you welded in a straight pipe, you'd have to weld in an 02 bung into it, and install the VAST 02 sensor into that?

[Bimmer2Audi]

bump

[Jung]

Yeah just make sure that the bungs are placed well enough so that you can fit the CELiminators in there with the 02's, since it's like 2 inches longer w/ the CELiminators on.

[CactusBiturbo]

I had test pipes made with flanges and had my cats cut out and flanges put on those. So I can switch them in and out for emissions, environmental guilt trips, etc. You could v band it instead.

[Jung]

that's a good idea ^

[lsc2g]

yea true.. in my province in canada we have no carb testing so i doubt i'd ever need to worry... i crave more sound with my APR stealth.. its too quiet.. i'm going to do pure cat deletes and see how it is then and if its not enough remove the middle muffler

[Bimmer2Audi]

Will the muffler shop have the pipe their or will I probably have to buy my own? Where could I find some plain old straight pipe?

[Das General]

Any muffler/exhaust shop should have the right size pipe.

[Bimmer2Audi]

Any muffler/exhaust shop should have the right size pipe.

Thats what i thought, thanks.

Another quick question: Does the new 02 sensor have to welded into the new straight pipe or where?

[Bimmer2Audi]

bump

[AudiSportB5S4]

if you really want a fast answer, call VAST and ask prince or mike. or frank lol whoever answers will tell you all you need to know

[Bimmer2Audi]

if you really want a fast answer, call VAST and ask prince or mike. or frank lol whoever answers will tell you all you need to know

Just did, and got all my answers.

I forgot to ask though, is it worth getting new DP gaskets?

[AudiSportB5S4]

lol, well thats good. they are the best. im not sure though, but i mean its always good to replace that crap if its cheap ya know. (i have no idea how much those are) lol. insurance is always nice to say you've changed em

[lsc2g]

bump

[The_Jerbel]

Yes it's worth it. If you want to avoid exhaust leaks, then do it.

[WMi_S4]

yo man, i called and talked to Prince today and he basically talked me out of doing just straight pipes all the way back....but my CELiminators should be coming tomorrow and we should be all set for Friday....and your car is gonna be a shitload louder than my petty little Tru-Dual once you go straight pipes :)