Golf MK7 2018 1.8 TSI Exhaust Modification Removed Secondary Cat

[mgshuheb]

Hello all, newbie here.

I'm not too familiar with the vocab around each part of the exhaust system - so please take it easy.

I recently had my stock exhaust cut and made into a straight y pipe. He removed the secondary cat and then welded on a straight Y pipe. Now I get no back pressure and so on so I want to change it and do it properly and buy this one: https://www.awe-tuning.com/mk7-golf-18t-exhaust-suite

Do you think if I had this installed I would be okay with no tuning needed? Also, my down pipe should be in tact with the primary cat, right?

 

[snobrdrdan]

You don't need tuning for a cat-back exhaust

But on the other hand...I'm not sure what you did with the "straight Y pipe" or whatever

 

[mgshuheb]

You don't need tuning for a cat-back exhaust

But on the other hand...I'm not sure what you did with the "straight Y pipe" or whatever

I was an idiot and didn't know much except that I wanted a Y pipe style exhaust - didn't even think of the ramifications of what I was about to do. My current setup up has the stock down pipe with only one cat as the secondary one has been removed.

 

[tigeo]

Which car here? Fwd or awd hatch or wagon?

 

[MeltedSolid]

So by Y pipe do you mean half the exhaust dumps out straight underneath the cabin?

 

[Sparky589]

Did the exhaust shop dump the cat or is it still lying around somewhere?

 

[mgshuheb]

Hello all - been Away a while - but this is an issue still. The cat has been dumped/sold I don’t know. I have one car still on there and the exhaust has been split into two pipes aka Y pipe.

 

[Fried_Soap]

Hello all - been Away a while - but this is an issue still. The cat has been dumped/sold I don’t know. I have one car still on there and the exhaust has been split into two pipes aka Y pipe.

The rear muffler is obviously gone and replaced with the dual-exit (Y) pipe, and it seems the resonator is still on the catback – but did they actually remove a cat on the downpipe? Or just chop off the axle-back and weld on the Y pipe?

This is the secondary cat, which should be visible under the car if it's still there?

 

[GTI Jake]

You’re getting some pretty bad information.

-that’s a muffler they removed, not a cat.

-there’s no such thing as “back pressure” on a turbocharged engine. The turbo equivalent is called “drive pressure” and it exists even without a exhaust at all (the exhaust pressure between the exhaust valves & turbine wheel of the turbo is drive pressure).

So in short you didn’t hurt anything (other than aesthetics & resale value) by having the muffler chopped off.

 

[GTI Jake]

Just for fun, here’s the only Mk7 Golf TSI muffler delete aka axle back aka Y pipe I’ve built.

It’s kind of a pointless mod because 1.8T with the original is12 is very quiet, even with the muffler removed.

 

[sherbet]

-that’s a muffler they removed, not a cat.

If referring to the pic OP attached with the component circled in red, that is in fact a secondary cat, but I assume you’re referring to the rear box where he had it cut and replaced with a Y.

PSA, if anyone removes a , or both from their car with no intention to re install ever, don’t just give them away to the shop doing the work…sell those bastards. I just sold a pair of secondary cats to a seller on FB that specifically buys used VAG cats to recycle….he paid me $600 for two 100k mile used secondary’s from my B5 that I had stuffed in a garage cabinet years ago and forgot about until I started cleaning earlier this year. Nice little bonus…and he would have paid me closer to $1k if I had kept the primary’s.

 

[GTI Jake]

If referring to the pic OP attached with the component circled in red, that is in fact a secondary cat, but I assume you’re referring to the rear box where he had it cut and replaced with a Y.

PSA, if anyone removes a , or both from their car with no intention to re install ever, don’t just give them away to the shop doing the work…sell those bastards. I just sold a pair of secondary cats to a seller on FB that specifically buys used VAG cats to recycle….he paid me $600 for two 100k mile used secondary’s from my B5 that I had stuffed in a garage cabinet years ago and forgot about until I started cleaning earlier this year. Nice little bonus…and he would have paid me closer to $1k if I had kept the primary’s.

The OP didn’t post the photo with the secondary cat circled, he posted the car on the lift.

I’m fully aware of what components are, I build a full line of parts for this platform.

 

[sherbet]

The OP didn’t post the photo with the secondary cat circled, he posted the car on the lift.

I’m fully aware of what components are, I build a full line of parts for this platform.

View attachment 265914View attachment 265915

I’m aware, hence my statement assuming you meant the rear section. Some nice work there sir. No offense intended.

My mistake on OP DP post.

I make my living working on cars as well, albeit with some funny looking Golf’s

 

[GTI Jake]

I’m aware, hence my statement assuming you meant the rear section. Some nice work there sir. No offense intended.

My mistake on OP DP post.

I make my living working on cars as well, albeit with some funny looking Golf’s
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The elusive SPICY VWs haha

I wouldn’t say I make a living, maybe break even at best doing Baun Performance on the side, fixing these pays the bills