Cat Delete test pipe or High flow cat??

[gregkoss]

Hello everyone,

I spend some hours reading opinions at this forum but I want some clear answers 'cause I didn't find what I was looking for..

My car is a 1.8 20VT Passat 2000 APU engine (150HP stock) and I have a chipped ECU and High flow air intake.. (mushroom)

I want to replace the Cat with a High flow one or to delete it with a test pipe.. but to leave the rest of the exhaust stock as it is..
Which is the best way to replace my stock cat?
1) High flow cat or
2) Test pipe

I saw that there are some 2.5" to 3.0" like the 034 Motorsport HF Cat.. or some test pipes..
Can I bolt them on the stock exhaust without any modifications? (The stock exhaust is 2.25" I think, isn't it?)

Thank you in advance..

[holywar0902]

I bolted the test pipe to my stock downpipe. It really depends on your needs and goals. Either way check engine light will surface unless you get it coded out.

[gregkoss]

I bolted the test pipe to my stock downpipe.

How the 2.5" (or 3") test pipe fitted on the (2.25") stock downpipe.. (Sorry for dummy questions.. )

It really depends on your needs and goals.

I just want to gain as much as HP and TQ it's possible..

Either way check engine light will surface unless you get it coded out.

With a spacer at the 2nd sensor I think that the CEL will go off.

[DISCLOSUR3]

The 42DD O2 spacer works wonderful to eliminate the CEL with the ECS tuning test pipe.

[gregkoss]

The 42DD O2 spacer works wonderful to eliminate the CEL with the ECS tuning test pipe.

Yes that is what I know..
What is your opinion about my queries?.. Anyone?

[scotts13]

Between the two choices, I'd recommend the high-flow CAT. Neither will make an appreciable difference in performance, might as well continue keeping pollution under control.

[gregkoss]

Thanks for your answer scotts13..

[Hydro-sweep]

I would recommend 034 HFC, they sell an optional O2 spacer kit with the cat. This is what I will be running on my wagon soon. I would encourage you to spend some extra cash and get the full exhaust, it will really make much more of a difference than just a hfc. TT makes a great system at an affordable price. Again, this is what I will be running. I spent alot of time researching everything out there and that system seemed the best bang for the buck to me. Just my 2 cents.

[holywar0902]

How? Its bolts right up. I think the one I have is 3in at the turbo and 2.5 at the downpipe. Bolts up like factory. I had a tough time with spacers. Hell I even had a tough time installing it. Want more power? Chip it. Most Programs have a cat delete file to kill the code that pops up when you remove the cat.

[gregkoss]

How? Its bolts right up. I think the one I have is 3in at the turbo and 2.5 at the downpipe. Bolts up like factory. I had a tough time with spacers. Hell I even had a tough time installing it. Want more power? Chip it. Most Programs have a cat delete file to kill the code that pops up when you remove the cat.

OK, I understand.. my ECU is already chipped and today I figure out that my car doesn't have the second O2 Sensor..

[holywar0902]

No second 02 sensor at all? Thats weird

[gregkoss]

No second 02 sensor at all? Thats weird

I search the Cat visual.. I couldn't see anything.. I put my hands and I search it.. Nothing.. I try with a mirror (like the dentist's) nothing again.. I even raise the car and I get underneath to search it.. I didn't find any (second) O2 sensor..

[scotts13]

Note the OP's location in europe. USA spec cars have a second O2 sensor to monitor the CAT; doesn't mean they're used everywhere.

[turb5o]

id run the high flow cat...the test pipe will make your car smell of unburnt gas a lot, and will not make you any more real power than a hfc. i tried the test pipe ad ditched it within aweek because of how bad it smelled of unburnt gas fumes in my car. i got acustom made100 cell hfc from a member on here, and i saw no drop in power going from the test pipe to the100 cell cat, and best thing was, on my aeb at least, i didnt needany spacer or anything for the rear o2 sensor and havent thrown a cel in the 1 1/2 years it been on there. go hfc for sure in my opinion.

[MikeyFresh]

No emissions here, so I went 3"-2.5" Test-pipe to stock downpipe (for now). If youre chipped you should notice a difference going from a stock cat to a HFC or Test pipe.

[gregkoss]

No emissions here, so I went 3"-2.5" Test-pipe to stock downpipe (for now). If youre chipped you should notice a difference going from a stock cat to a HFC or Test pipe.

I have a friend on the "emissions test center" so there will be no problem for me.. Yes I am chipped.. Does the test pipe smells, like turb5o said at previous comment? or did you notice anything else??

i didnt needany spacer or anything for the rear o2 sensor and havent thrown a cel in the 1 1/2 years it been on there. go hfc for sure in my opinion.

..also, I don't have a rear sensor.. only the first one..

[holywar0902]

Dam I didnt notice you were in greece. Yes the test pipe smells. I dont smell it inside but I do outside or if I have the window down and I back up I can smell it....only because I backed into the smell.

[NUISANCE]

If you put a test pipe on you aren't exactly dumping toxins in the enviroment. I had a test pipe on and passed the CA Smog test via the sniffer with flyinh colors, but failed the visual. It's not always the cat that keeps the toxins down, the tune plays a huge role too.