Any ideas what this could be please?

[Norwichdaz]

Yeh reckon so and deffo more suction trying to take oil cap off now.

Yeh the clip i know isn't perfect etc but the more I even type into YouTube even wastegate rattle in general they all.sound the same and like mine and u see some do the clip, some new turboand some new wastegate replacement.

[Norwichdaz]

Had this on the scan today as to see why engine light on, weirdly, had these codes when had new plugs,coils etc last week lol..
New purge a month ago...
Trying to eliminate things,

Still not sure where this air leak is so might do a smoke test..
And with the 2 different banks, iv seen possible 02 sensor failures and/or maf too or at least try cleaning it.

[Nino]

So all of them codes are linking to the ECU or the Lamber not getting the readings its expecting.

I had a similar issue on one of my R32's TWICE 

First time is was the brake servo hose near the back end of the engine that had a split, the second time it was a faulty MAF sensor.

Thing is with VWs you can have something as small as a split in a hose which then causes multiple sensors to go out of wack.
Clear the codes off, it might be "pre PCV" and didnt have the codes cleared down.

If the codes come back that I would get looking into the entire system, start with the cheapest things first.
Check your Diverter Valve part number, if it doesn't end in "D" then you will have the Diapham model which is prone to splitting, the "D" version is the Piston version.

But here is a break down of the codes which should help you check things.

P0172 – System Too Rich (Bank 1)
The ECU detects the air–fuel mixture is richer than expected.
Common causes:
- Faulty or dirty MAF sensor
- Leaking fuel injectors (on Mk6 GTI this is very common)
- High fuel pressure (faulty fuel pressure regulator or HPFP issues)
- Evaporative emissions purge valve stuck open
- PCV (positive crankcase ventilation) valve failure
- O2 sensor issues (usually front sensor)

P0441 – EVAP Incorrect Purge Flow
The EVAP system isn’t controlling vapor purge correctly.
Common causes:
- Faulty N80 purge valve (very common VW issue)
- EVAP leaks or stuck purge solenoid
- Blocked EVAP lines or charcoal canister fault
- Wiring fault to purge valve

P0303 – Cylinder 3 Misfire Detected
Misfire specifically on cylinder 3.
Common causes:
- Bad coil pack on cylinder 3
- Faulty spark plug
- Failing fuel injector (very common on Mk6 GTI)
- Low compression (carbon buildup on valves, worn rings, etc.)
- Vacuum/PCV leak affecting a single cylinder

If I had to take a guess, because you have already replaced the PCV, Sparks and Coils, its most likely going to be a faulty purge valve (N80) This is the single most common cause that can realistically trigger all three of your codes at the same time.

- It directly sets P0441 when it sticks open.
- When stuck open, it feeds unmetered fuel vapors at idle → rich condition → P0172
- That sudden enrichment commonly causes misfires, especially on one cylinder that happens to be most affected → P0303

On Mk6 GTIs the N80 is a very high failure-rate part. Cheap, easy to test, and easy to replace.
Simple way to test and replace the N80 purge valve, On the right side of the engine bay, attached to a hose coming from the charcoal canister. Looks like a small black plastic solenoid with an electrical plug. If you follow the hose coming off the intake tube (near the airbox), you’ll see it.

Remove the N80 valve from the hoses (very easy just hose clamps). Try blowing into one end of the valve with the valve unplugged (no power), it should NOT let air through.

If you can blow air through it with no power → it’s stuck open → BAD valve. Buy a new one and replace it, the part number should be written onit somewhere. Should be under £50, just order it via your local VW or TPS (Don't use a 3rd party or used part)

You can also do a shake test, Not definitive alone, but helpful. Shake the valve about whiles its in your hand.
- Normal: It should click/ratttle lightly
- Bad: No sound, or sticky feel

[Norwichdaz]

Thanks for all that  👌

The pic is the purge valve i had fitted last month but..... the connector was too small i think for the connection part so the mechanic where I work cut the wires crimped them so that it would still fit this purge... and said was clicking and working fine , and the garage who did the work last week said they checked it too and said was working fine tbf..

U say lamba,  isn't that basically one or both of the o2 sensors? Been looking online alot lately haha..
Not checked DV but I wouldnt have thought it would be the new style.

The light is off after clearing it today , so will see if/when comes back but as I said to the garage its running fine.
They said they took it out for a spirited drive too and said had plenty of poke lol so maybe turbo is ok, that noise is just this wastegate issue ...

[Nino]

Ahh ok, that’s useful info.
If the purge valve you fitted needed the wiring cut and re-crimped, then just keep in mind there’s a small chance it could still be part of the problem. The valve itself might click, but a poor connection or slightly different spec can make the ECU behave strangely with EVAP/trim logic. Not saying it’s definitely the cause, just something to keep in the back of your mind if the codes come back.

On the lambda/O2 front yes, lambda sensor is another name for the O2 sensor. The trims you were getting earlier can be caused by a sensor reporting what it’s seeing (i.e., rich mixture) rather than the sensor failing. They usually get blamed, but they’re often just the messenger.

The DV is definitely worth a quick check. The original diaphragm style (pre-revision-D) can split without giving you huge performance loss sometimes just a soft “blow” noise on lift-off. The car can still feel “pokey” but the trims go out of whack because of the metered air escaping.

As for the turbo itself, yeah, wastegate rattle wouldn’t cause misfires or rich trims, so the garage saying it still pulls well makes sense. The wastegate clip fix is really only for the rattle, not running issues.

Main thing now is just to see if the light comes back. If it does, I’d still 100% go ahead with the smoke test, because even a tiny leak can cause exactly the symptoms you had. Given the PCV had failed, it’s very common for another hose or joint to be leaking somewhere in the system.

Keep us posted you’re getting there! 

[Norwichdaz]

Awesome ! Haha thank-you,

Yes deffo think getting there fingers crossed haha 

Yes guess cant hurt on the dv front...

So you mean the o2 could be ok but just a faulty sensor possibly?

I keep seeing a lot about mafs.... I was going to take it out and clean it (with the correct spray)
But maybe il do that if starts playing up again incase it it made it play up again? Lol..