# Unusual P0299



## AngryGiraffe (Sep 21, 2014)

So yesterday while getting on the throttle my CEL came on. Had a mechanic scan it and it was P0299: turbo/super charger boost sensor (A) circuit: Control limit not reached. Searched the forum and mostly what I found was people having problems with their diaphragm DV going bad. I already updated my DV to a piston style before I had my tune done. I decided to put the car up and check the bolts on the DV to see if maybe they were loose and causing a leak. I noticed two of the bolts were less than a 1/4 turn loose. Cleared the CEL and went for a drive. It seemed like it might have had a little more lag than normal, but that could have just been in my head. Other than that the car drove/sounded fine and the light is still out(for now) has anyone else had this problem or had a Pierburg piston DV go bad on them? Could there be a leak in a hose?


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## body electric (Aug 27, 2002)

Very common problem, that code showed up on my 06' GLI and I had to remove the DV and replace it with an aftermarket one from ecs tuning.










Sent from my iPhone using Tapatalk


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## 2006_A3_2.0T (Jan 11, 2013)

body electric said:


> Very common problem, that code showed up on my 06' GLI and I had to remove the DV and replace it with an aftermarket one from ecs tuning.
> Sent from my iPhone using Tapatalk


I think he already has the piston type DV. on the left


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## vwlippy (Jul 17, 2001)

I've had the new style DV valve in since I got GIAC tune about 50k miles ago. 
No problems since.


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## AngryGiraffe (Sep 21, 2014)

Already replaced the DV with the piston style one. It's in the post. That's why I can't figure out why the CEL came on with this code. It's been out for two days now but I have only put 20 miles on it. Tomorrow I plan on going up to the mountains and doing some real driving to see if it will come back on. I wish I had a boost gauge to see if there is any pressure loss.


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## Audi_Mechanic (Mar 24, 2012)

Check the waste gate actuator rod where it meets the waste gate pivot. If it wiggles then it's time for a turbo.


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## AngryGiraffe (Sep 21, 2014)

Audi_Mechanic said:


> Check the waste gate actuator rod where it meets the waste gate pivot. If it wiggles then it's time for a turbo.


Oh **** I hope not! It's only got 48,000 miles on it. I don't want to have to buy a new turbo. That will kill my mod budget for years.


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## louiekaps (Aug 12, 2013)

If it is bad get a k04


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## TBomb (Sep 23, 2009)

AngryGiraffe said:


> Oh **** I hope not! It's only got 48,000 miles on it. I don't want to have to buy a new turbo. That will kill my mod budget for years.


The TSI engine is popular enough you could probably find a used K03 turbo for cheap somewhere, either someone who upgraded or a salvage yard. Or yeah, just do what Louie said 



louiekaps said:


> If it is bad get a k04


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## AngryGiraffe (Sep 21, 2014)

Well CEL came back on yesterday. I can only imagine that it's the same thing. Turned off my tune and am driving it as little as possible. I have an appointment at the shop that did the tune on Tuesday to have it checked out. Sucks! It's such a nice day outside and I would love to go for a drive in the mountains.


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## AngryGiraffe (Sep 21, 2014)

*Problem solved!*

Brought my car to BlueWater Performace yesterday and they did a boost pressure test. Turns out My PCV was shot. Looked simple enough to replace myself, and I get a parts discount at work so I figured I would save some money on labor. Installed it after work, turned my tune back on, and went for a ride. Car runs great! So relieved it wasn't my turbo.


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## Audi_Mechanic (Mar 24, 2012)

By PCV do you mean the breather valve mounted on top of the valve cover? If so, I don't recall seeing a failed unit setting a P0299 code. They usually set idle speed and intake leak faults, sometimes misfire and fuel/oil pressure faults. Just today I replaced one on a Q5 2.0t. Had codes P0506 & 507 for idle speed, some random misfire faults, P2187 and 2279 for intake leak, and P119A for fuel pressure, total of 8 codes.

Most often they fail in a way that makes it very difficult to remove the oil fill cap while it idles and they suck in air through their diaphragm weep hole. I took a video on how to test a failed breather without scanning the car:


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## AngryGiraffe (Sep 21, 2014)

That is what I replaced. I didn't personally do the boost pressure test, but that's what they said it was. I did notice that when I tried to take the oil filler cap off a few days prior it was hard to get off but it wasn't while it was idling, it was off and hadn't been started for close to an hour.


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## AngryGiraffe (Sep 21, 2014)

*Ugh! P0299 is back again!*

:banghead:On my way home from work my cel came on. Scanned it and decided to look under the hood and see if anything had come loose over the winter. While I was nosing around I decided to take off the oil cap. When my pcv went bad last time it was hard to get the cap off and as soon as you did you could feel the suction and the car started to idle rough then stalled. Tonight the cap wasn't hard to get off, but as soon as it was off once again the car started to idle rough and you could feel suction. It didn't stall and once the cap was back on the idle returned to normal. I already replaced pcv and dv(piston style)with the updated versions and my tuning shop did a boost test and said there were no other leaks, but that was 6 months ago. At the time they said there was a hairline crack in my APR carbon stage 2 intake pipe maybe over the winter it has gotten worse? Tomorrow I am switching it back to the stock pipe and will wait and see if the light comes back on? I could see the pipe maybe causing a small leak and a cel, but would it cause the oil cap issue? Could the new updated pcv gone bad already? At this point I'm considering getting a catch can and by passing the pcv altogether. I really don't want to go this route but I don't know what else to do. I am however worried since it gets pretty cold here in the winter and have read stories of people having the lines/cans freeze where they live. I guess I could just make sure I empty it monthly or by weekly in the winter. So I was wondering how do you guys like your catch cans? Were they easy to install? Is it easy to drain? And if you had to get another one would you get the same one or would you go with a different brand? Any ideas on what's causing this problem or info on cans would be great.


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## BeeAlk (Jun 3, 2013)

AngryGiraffe said:


> :banghead:On my way home from work my cel came on. Scanned it and decided to look under the hood and see if anything had come loose over the winter. While I was nosing around I decided to take off the oil cap. When my pcv went bad last time it was hard to get the cap off and as soon as you did you could feel the suction and the car started to idle rough then stalled. Tonight the cap wasn't hard to get off, but as soon as it was off once again the car started to idle rough and you could feel suction. It didn't stall and once the cap was back on the idle returned to normal. I already replaced pcv and dv(piston style)with the updated versions and my tuning shop did a boost test and said there were no other leaks, but that was 6 months ago. At the time they said there was a hairline crack in my APR carbon stage 2 intake pipe maybe over the winter it has gotten worse? Tomorrow I am switching it back to the stock pipe and will wait and see if the light comes back on? I could see the pipe maybe causing a small leak and a cel, but would it cause the oil cap issue? Could the new updated pcv gone bad already? At this point I'm considering getting a catch can and by passing the pcv altogether. I really don't want to go this route but I don't know what else to do. I am however worried since it gets pretty cold here in the winter and have read stories of people having the lines/cans freeze where they live. I guess I could just make sure I empty it monthly or by weekly in the winter. So I was wondering how do you guys like your catch cans? Were they easy to install? Is it easy to drain? And if you had to get another one would you get the same one or would you go with a different brand? Any ideas on what's causing this problem or info on cans would be great.


I would go with a CC setup if you dont feel like dealing withe PCV issues ever again. 

It gets cold here in the winter too, I've never had in issue with freezing lines or any explosions. Mine is the Eurojet ammo can setup (discontinued long ago). Only thing I don't like about it is that the drain is too small, so the slightest amount of sludge plugs it up. Right now I just have a hose running from the drain down towards the ground with the drain open. I plan on drilling and tapping a larger hole with a bigger fitting to allow the junk to flow out more easily.

First though, I'd fix your intake. You're talking about the pipe that goes to your air filter? Can't see how it would cause your particular issues, but that should really be fixed.


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## AngryGiraffe (Sep 21, 2014)

BeeAlk said:


> I would go with a CC setup if you dont feel like dealing withe PCV issues ever again.
> 
> It gets cold here in the winter too, I've never had in issue with freezing lines or any explosions. Mine is the Eurojet ammo can setup (discontinued long ago). Only thing I don't like about it is that the drain is too small, so the slightest amount of sludge plugs it up. Right now I just have a hose running from the drain down towards the ground with the drain open. I plan on drilling and tapping a larger hole with a bigger fitting to allow the junk to flow out more easily.
> 
> First though, I'd fix your intake. You're talking about the pipe that goes to your air filter? Can't see how it would cause your particular issues, but that should really be fixed.


I can't either, but at this time I don't know what else it could be. It's the second pipe. So it's the one after the air filter and MAF(going to check the MAF tonight as well)I'm doing some other work to the car this weekend while I have it up in the air I plan on checking all of the hoses to and from the turbo and making sure all the bolts on the diverter valve are tight as well. So correct me if I'm wrong but you are basically leaving the catch can open at all times with a hose attached to the drain. I think I've heard it called draining to atmosphere.


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## BeeAlk (Jun 3, 2013)

AngryGiraffe said:


> I can't either, but at this time I don't know what else it could be. It's the second pipe. So it's the one after the air filter and MAF(going to check the MAF tonight as well)I'm doing some other work to the car this weekend while I have it up in the air I plan on checking all of the hoses to and from the turbo and making sure all the bolts on the diverter valve are tight as well. So correct me if I'm wrong but you are basically leaving the catch can open at all times with a hose attached to the drain. I think I've heard it called draining to atmosphere.


Mine is a VTA (vent to atmosphere). This is considered bad (immoral) because it sends NOx into the air, instead of back to your motor to get burned up further. The can collects the heavy oil and a lot of the vapor condenses and collects in the can as well, but the pressure and remaining vapor exit through a small filter on top of my can. I wanted to NOT send **** back to my motor at all, so sorry tree huggers. If it makes up for it, I'll use my leaf blower one less time this year. 

The other method is referred to as recirculating as it pipes the air that goes to the can back to the valve cover, the can acting as a trap which collects the majority of the gunk (I guess). 

If you have a VTA setup and you forget to drain it, oil an goo will start to work its way out of the vent, making a mess of things. If you have a recirculating setup and forget to drain it, it will start getting picked up and blown into the valve cover in large quantities. 

I've been having issues with my drain, so that's why I've been leaving it open for now.


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## Audi_Mechanic (Mar 24, 2012)

> Tonight the cap wasn't hard to get off, but as soon as it was off once again the car started to idle rough and you could feel suction. It didn't stall and once the cap was back on the idle returned to normal.


This is normal. The crankcase is part of the intake system, so any large leaks will make the engine run differently. Forgetting to install the oil cap or dipstick will eventually lead to an engine MIL. As combustion gases get past the piston rings, they build up inside the crankcase. The valve you had replaced controls how quickly the gases are vented to the intake manifold or to the turbo when under boost so that the gases can be burned in the combustion chambers.

When you're looking your car over, check the turbo's waste gate actuator rod for play.


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## AngryGiraffe (Sep 21, 2014)

BeeAlk said:


> so sorry tree huggers. If it makes up for it, I'll use my leaf blower one less time this year.


 :laugh:



Audi_Mechanic said:


> This is normal. The crankcase is part of the intake system, so any large leaks will make the engine run differently. Forgetting to install the oil cap or dipstick will eventually lead to an engine MIL. As combustion gases get past the piston rings, they build up inside the crankcase. The valve you had replaced controls how quickly the gases are vented to the intake manifold or to the turbo when under boost so that the gases can be burned in the combustion chambers.
> 
> When you're looking your car over, check the turbo's waste gate actuator rod for play.


Ok I will check it. should it have play? If so about how much?


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## AngryGiraffe (Sep 21, 2014)

So I figured if I was going to check the stage 2 pipe I might as well clean the filter and MAF sensor. Once I got the whole thing apart I saw this 

And that connector goest directly to the pcv. Which is probably what's been causing the issues with it. Probably not going to fix the p0299, but hey it's a start. I am going to see if one of the body techs in my shop can repair it. Ever since I got the pipe the connector never fit well and I'm guessing it somehow cracked it. The clip just doesn't fit flush. Was wondering what I can put around the connector to make it fit better? If we can repair the pipe I'm going to have to slot the mounting hole for the pipe so it fits more flush. I think it's causing a bunch of unwanted pressure on this area. Also it has caused this to happen as well. 

Does any one know where I can get a replacement flex section. I'm sure it's probably ok but I wouldn't mind replacing it just to be sure. I would also like to replace the other section that is supplied with the intake since it's a ridged piece of hose and I would like it to have more flex so the carbon doesn't crack again.
I cleared the code and will see if it comes back on over the next few days. I still plan on checking everything turbo related this weekend to make sure nothing has come loose.


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## Audi_Mechanic (Mar 24, 2012)

AngryGiraffe said:


> should it have play?


Should be under constant tension, so no play.


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## Audi_Mechanic (Mar 24, 2012)

I was at work today and couldn't make time to reply to your pm. You will find the waste gate actuator from below. Will be between the turbo and engine block.

Here's a link to ECS' website that shows a turbo for CCTA 2.0T, CBFA will be similar:https://www.ecstuning.com/Audi-A3-Quattro-2.0T/Engine/Turbocharger/OE/ES2702442/

The first picture shows the actuator, which is the gold colored cylindrical unit. It has a small diameter pressure hose attaching it to the wast gate control solenoid N75. The fourth picture shows the underside of the turbo and in it you can see the actuator rod going to the waste gate flap arm.

Other causes of low boost aside from a worn out waste gate are boost leaks, air/fueling problems (you'll probably have other codes), problems with the waste gate control solenoid or recirculation valve, leaking actuator diaphragm. If the actuator rod is tight, then a boost leak test should be performed. You can take a look at specified/actual boost pressures under load and see if they match.


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## AngryGiraffe (Sep 21, 2014)

Saturday while I was checking lines for leaks I got with one of the body techs at my shop and fixed to stage 2 carbon intake pipe. First step was to fix the crack. 

We decided to fill the crack from the inside and then try to seal the rest of the inside just incase it tries to crack again. Maybe this time it will try and crack the panel bond before the carbon. I let it sit for 24 hours and then lightly sanded the inside smooth. Still leaving some material behind. This also helped the connector sit a little more even/flush.

Next it we took a small dremal tool and notched the side of the mounting bracket. Not the cleanest cut but this is how it had to be cut so it could/would fit without it putting to much pressure on the sensor. Luckily it sits behind the mounting bracket on the engine. Might have to cut it a bit further if it continues to put stress on the pipe. Took the car on a short(1-2 hour round trip spirited drive) and got it above 5000 rpm's a few times. So far no leak, but this problem seems to go away for a few months and then slap me in the face when I come walking around a corner not paying any attention. I guess time will tell.


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## MisterJJ (Jul 28, 2005)

Is that J-B weld?


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## AngryGiraffe (Sep 21, 2014)

Haha! No it is 3M panel bond.


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