Installed a straight pipe, car stinks

Before you throw rocks at me: I am aware of the EPA rules and pollution.
I have installed a GTB1749V turbo from Darkside along with a egr delete and a straight 3" stainless steel pipe. I have to leave the garage door open for 10 minutes to get rid of the exhaust stink after I back the car up. Also, while in traffic, especially when I'm in bumper to bumper traffic, I get the occasional diesel exhaust "fragrance" in the car.
Still have the catalytic converter, I wonder if I re-install it, will it keep up with the bigger turbo and a Stage 4 tune from Malone without getting damaged?
How about from a performance point of view: what are the benefits of having the converter removed?
If I will end-up re-installing it, should I clean it first? If yes, using what?

A cat, either stock or aftermarket will reduce the odor.

Other than higher egts, no drawback other than less turbo sound.

Are you 100% sure you do not have an exhaust leak? If the leak was on the straight pipe side you would hear the turbo whistle, so maybe you have a leak at the junction of the head and exhaust manifold possibly?

mrchill said:

A cat, either stock or aftermarket will reduce the odor.

Click to expand...

I'll second that.

Nevada_TDI said:

Are you 100% sure you do not have an exhaust leak? If the leak was on the straight pipe side you would hear the turbo whistle, so maybe you have a leak at the junction of the head and exhaust manifold possibly?

Click to expand...

I am pretty sure that the nuts at the head and exhaust manifold connection are pretty tight, I have used new nuts. I will double check them. I had an exhaust leak at the turbo-exhaust pipe connection, the exhaust pipe was used and had some imperfections. I have used JB weld extreme heat to cover the circumference of the turbo-exhaust connection.
Still, I had someone turn on the car and noticed a brief small smoke "cloud" of exhaust coming from the back of the engine. That happens only when the engine starts.
Regardless, the car stinks pretty bad. I have stopped driving it until I fix it. With this setup, I cannot park it in the garage, the stench lingers for 20 minutes after I turn off the engine, while the garage door is open. Yesterday was warm outside, I still had the winter bra on my car and while driving the coolant temperature reached 202F. I have stopped for minute to remove the lower bra, as soon as I have exited the car the stench hit me.
Still have the CAT, I'll probably end up reinstalling it.

Only noticeable difference I had when installing a high flow cat was mid-range boost. Although Im speaking of a 2003 Suburban, 5.3L with a 70mm turbo. Straight piped it was insane, but I sold it to an out of stater that needed to pass a visual, so installed a 3" in/out Flowmaster high flow cat. Although the buyer will never notice a difference, I could because I was able to drive it without the cat.

When the cat is cold you may still notice the smell until it heats up. Once it heats up then the catalyst can perform its function and may reduce the smell.

Maybe it’s your JB Weld

Yeah, you have a leak, and jb weld is not the solution.

jmodge said:

Maybe it’s your JB Weld

Click to expand...

It's definitely not the JB Weld. As a matter of fact, it did a good job where I have used it.

Ok, but we just had a north wind and I swear I could smell JB Weld burning

jmodge said:

Ok, but we just had a north wind and I swear I could smell JB Weld burning

Click to expand...

I appreciate your humor. It could not have been my JB Weld smell, I'm located towards your South-East (Macomb County). As of now, the car sits in the garage, I'll take a look at the issue over the weekend. I have also found out that Magnaflow sells a high-flow stainless steel catalytic converter for a decent price. I'm considering buying it.

Removing the EGR causes noticeable smoke at start up.

2footbraker said:

Removing the EGR causes noticeable smoke at start up.

Click to expand...

As a matter of fact, significantly less smoke at start up with a EGR delete, catless straight pipe, and Malone Stage IV tune, compared to stock emissions, and muffler. But stink-wise, a totally different story.

You are aware you are driving a diesel?

iamatt said:

You are aware you are driving a diesel?

Click to expand...

Brother, I had the car for 7 years, of course that I am aware that I am driving a diesel. The key thing is that until recently the car had all the stock emissions equipment. Now it does not. Have you ever experienced the stink of a diesel exhaust with no EGR, no catalytic converter, just a straight pipe? When you will, maybe you'll understand what I mean.

On my first mk4 wagon I started getting a lot of stinky fumes in the car, turned out it was just the very end of the tail pipe from the back box had broken.
I was quite surprised that extra foot or so made.

On my latest tdi there was a hole near the middle, no stink, no fumes.

It's funny how a leak in different places can have such an impact or none.