do your emissions places test awd cars under load or just hook them up to a computer? if they dont test cars under load you can do the non-fouler mod. if they do, you can get a hfc.

 

actually my dad is about to open an emissions place and 96 up cars are tested by the computer. even then, i wouldnt doubt it if would pass, my 4.0 wrangler passed 5 years ago with no cat at all. they may have gotten stricter now. so what is this mod and what are the pros and cons of it? cost?

 

Yes, That was me who said that about the flex pipe. When I had my passat, my flex pipe broke. A non-oem flex pipe was put in as replacement and the turbo spooled a little louder and higher pitched. About two weeks ago, the flex pipe broke on my 2001 A4 TQM. (I've only had this car for a month but the engine is identical to the passat I had, under the hood practically everything looks the same) Anyway, I went to a local muffler place because I was desperate, I had to go to class and I needed my car and it wasn't reaching over 30 MPH. They put in a flex pipe which I noticed was about 1/4' to 1/2' smaller in diameter. (Please don’t be offended), but you guys who say it's not can not say for sure because you have never done it. You are only speaking from what you THINK may be true. You can not say it's not true when it happened to my twice.

Just sharing with everyone what happened to me............when smaller diameter, non OEM flex pipes were installed on my cars, my turbo got louder.....I didn't want it to, it just did.

 

i believe it for sure, cause i know exhaust affects that turbo whine alot......but are you sure its because of the diameter of the flex pipe? maybe its just the material. frankly, i'd like to know what exactly was put in there cause i want more whine.

 

if its tested by the computer it will pass. they used the same method as 5 years ago, they just scan for codes. with the non-fouler you raise the o2 sensor out of the exhaust stream and trick it into reading better. the CEL could come back every once in a while but you'll pass the emission test. its a couple bucks at autozone. or you can get an angle block. there's a guy named Wayne over on vortex who sells them. it works better than the non-fouler in that the CEL doesn't keep coming back every once in a while but its a little more expensive

 

the whine becomes louder when you break the flex pipe cause your exhaust is now exiting through there instead of going through the mufflers and out the back. i'm pretty sure there's a flex pipe there cause of engine movement. if there was no flex pipe to absorb the movement of the engine your exhaust could crack.

just replacing the flex pipe isn't really gona make the turbo louder, im still running the stock flex pipe with my techtonics exhaust and ecode tp and you can hear my turbo as clear as day

 

he was saying the new (non-broken) flex pipe made the turbo louder. and i do know what the flex pipe is now.

 

then he has super sensitive hearing cuz just changing the flex pipe wont make the turbo louder.

 

1- how did the diam of the flex pipe change? then it wouldn't fit the rest of the exhaust...
2- pretty sure most of us giving feedback (at least me) have swapped the intake, tp, and exhaust before, so we're not talking bout what we THINK is true, but what we experienced

 

What if the sudden restriction is bottlenecking the sound waves. Maybe because of that, they are contricting, and some sound waves are exiting the pipe, instead of running down the tube to get muffled by exhaust.