PPE Catless Downpipes: Smoking Exhaust

[SRT82ECOBOOST]

I am starting this thread as a follow up to my troubleshooting thread for white/blue smoke out the passenger side exhaust. I have determined that the culprit for the smoke can be attributed to the PPE catless downpipes I had installed. I am also not the first member to have this happen with these downpipes:
http://www.ecoboostperformanceforum.com/index.php/topic,339.0.html
Rather unfortunate that I paid good money for a product (plus install and removal) to get nothing but a smoke bomb. OEM downpipes are back on and the smoke is gone. PPE catless downpipes will be for sale shortly unless a budget based solution can be found.

[AndyMan04]

sorry to hear about those pipes man. I am looking to do the PPE's next spring along with a complete exhaust kit as well... I wonder what is causing you to smoke out like that. ..... I hope you find a solution man.

[SHOdded]

Let's hope that a failing/leaky turbo is the real culprit, as mentioned in another thread.  Catalytic converters cover up a lot of problems going on within the engine, and catless is like running bare naked truth.

EDIT:  Just saw the dealer unable to reproduce issue.  Maybe you can have your speed shop look independently at the turbo to make sure it's not leaking?

[SRT82ECOBOOST]

Let's hope that a failing/leaky turbo is the real culprit, as mentioned in another thread.  Catalytic converters cover up a lot of problems going on within the engine, and catless is like running bare naked truth.

EDIT:  Just saw the dealer unable to reproduce issue.  Maybe you can have your speed shop look independently at the turbo to make sure it's not leaking?

My speed shop checked out the turbo and he said that the turbo was not failing. This is not a problem that is only for the Ecoboost platform, but I know that the Mazda crowd suffered through the same problems with their turbo engines after adding downpipes.

[Brucelinc]

How could downpipes CAUSE smoking??  I agree with SHOdded.  The cats are cleaning it up but something could still be going on....

[EcoPowerParts]

Just curious guys, how many of you have catless downpipes and have no smoking issues?


Just FYI TONS of information about turbo cars and smoking after catless downpipes.
https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1FDUM_enUS479US479&ion=1&espv=2&ie=UTF-8#q=catless+downpipes+cause+smoking&spell=1

Please don't blame our product for your car having a mechanical issue.

Mazdaspeed forums

They're trying to be nice and not flame the crap out of you. This topic has been beaten to death over the years. Downpipes don't cause smoking turbos. Your restrictive, very efficient at cleaning the crap coming out of your engine, factory cat masks the problem you already had. When the factory cat goes away, your problem is revealed.
In the interest of full disclosure, there are some who believe that the greater backpressure of the factory cat somehow supports the turbo seals and keeps them from leaking oil. I'm not getting involved in that debate.

BMW 335i forums

I don't think you've fixed anything. Most probably your cats are just burning the smoke once it gets in them. This is what they are designed to do: reduce emissions. Chances are you either have a leaking turbo seals or there is a lot of blow-by gases causing oily air to be mixed with clean air through the PCV system.

VW forums (after installing catless downpipes and complaining of smoking)

it looks like the problem is resolved!!!


turbo replacement appear to fix it.


my diagnosis is oil seal in the turbo leaking oil to the exhaust side.

That being said when you had the downpipes R&R'd did your installer find oil at the turbo? I would have pulled the intake tube for the turbos and inspected both sides while the car was on the lift. When you went to the dealer they didn't pull anything apart, they just drove the car and said, hmm no smoke (because the cats burn the smoke off).


If I were you I'd buy the $1000 upgraded stockers on here and slap them on, more power and fix your issue, install those and the catless downpipes and viola no smoke!

[SRT82ECOBOOST]

I will further investigate the possibility of the turbo leaking oil/coolant to determine if that may be happening and look for a replacement if needed.
But regardless, there was no smoke out of my exhaust prior to the downpipe install. So I think it needs to be mentioned that if you put catless downpipes on your vehicle your may be looking at an expensive repair bill to replace your turbo if you don't want to look like oil burning clunker going down the road. I may be part of the uneducated few that did not realize this as a possibility, but it should be known that this could be the same road you are traveling down.

[EcoPowerParts]

You are making an incorrect assumption, you had leaking turbos before you put the downpipes on and your factory cats burnt off that smoke, now with catless pipes you are actually seeing that you have had a problem with your turbos for awhile but the smoke isn't burnt off.

It's not the pipes causing the issues, it's the pipes not burning off the smoke from your turbos. That's not a downpipes issue, it's a turbo issue, you just weren't aware before.
Your mechanical issue eventually would have caused oil into the cats and damaged cats, the good thing is your dealer would have been able to diagnose a complete failure easier unfortunately. You'll get there long term with your "fix", hopefully you don't off load this car onto someone else with a major mechnical issue for them to get stuck with.

[SRT82ECOBOOST]

I completely understand the situation at hand. Exactly how many people out there may have leaking turbos will not be known with the cats in place. The general public deserves to know that when you got to catless downpipes you should be prepared to have a stash of cash or be willing to work will the dealership for warranteed replacement of the turbos as they may be failing and will only know following the install of the catless downpipes.

[SRT82ECOBOOST]

So I am trying to surround myself with the best information possible on this topic. I am coming across an uncountable number of threads on various car forums where people are claiming the removal of back pressure with aftermarket downpipes can be contributed to the leaking of turbo seals. Then when going back to stock downpipes and therefore increasing the backpressure that the turbo leaks are no longer found on the turbos.
What are the opinions out there on this theory?

[EcoPowerParts]

There's no 100% on what you're saying, many many people with catless pipes and no turbo issues. The key is you can't tell if you're having a turbo issue with catted pipes until the turbos are horribly gone and puking oil into the cats. It's not the problem of the catless downpipe as you're suggesting.

Guys with catless downpipes from LMS, SW and PPE can all weigh in on this, I would bet there's quite a few with no issues.

You're putting an A = B correlation on this and that's not the case.

Love to see LMS weigh in on this, I'm sure they've sold WAY MORE catless pipes than I have.


Your specifically pointing on PPE downpipes as causing your issues and you're dead wrong on that.

[SRT82ECOBOOST]

Same issue as me as posted on this forum:
http://www.ecoboostperformanceforum.com/index.php/topic,339.0.html
I am just trying to find the root cause to this issue which is partially based on whether or not the lack of back pressure from aftermarket downpipes can cause turbo seals to leak. I don't know this to be fact, but there is enough mention across the world wide web of this happening to warrant some more research from me.

[SHOdded]

I will further investigate the possibility of the turbo leaking oil/coolant to determine if that may be happening and look for a replacement if needed.

Looking forward to what you find, if anything.  You shouldn't have to face this situation, it's hard to be the exception/statistic.  For general knowledge purposes, oil changes are being done by the dealer?  Maybe go to full synthetic?  Also, check the plugs to see if they have a story to tell.  The SHO is otherwise operating correctly?  No unexpected hesitations or turbo spikes etc.?

[SRT82ECOBOOST]

I will further investigate the possibility of the turbo leaking oil/coolant to determine if that may be happening and look for a replacement if needed.

Looking forward to what you find, if anything.  You shouldn't have to face this situation, it's hard to be the exception/statistic.  For general knowledge purposes, oil changes are being done by the dealer?  Maybe go to full synthetic?  Also, check the plugs to see if they have a story to tell.  The SHO is otherwise operating correctly?  No unexpected hesitations or turbo spikes etc.?

Maintenance is being done by the book and by the dealer. I am running a full synthetic. The plugs have been pulled and show no signs of anything suspect. There is no related degradation of performance that I can perceive with smooth delivery of power at all speeds and a smooth idle.

[EcoPowerParts]

It's not a PPE downpipe issue if you want to blame catless pipes in your head fine but blaming PPE vs LMS vs SW downpipes is ridiculous.
Is your position that PPE downpipes cause your issue and if you went LMS catless pipes you would be fine or SW?
Do you see what I'm saying, you're blasting a brand specifically and it's not a brand issue period.

Start reading here:
https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1FDUM_enUS479US479&ion=1&espv=2&ie=UTF-8#q=catless%20downpipes%20cause%20smoking%20site%3Amazdaspeedforums.org

You'll see that the default response is NO the catless downpipes don't cause they issue they expose it.
This is the response from those who know how turbos work over and over again.
Your statement would mean that EVERY race car with turbos and a short downpipe (think 18-30" of actual downpipe open to the ground) would cause turbo failures, that's not the case.