1.8t PCV SYSTEM PROBLEM, FAULTY "HOCKEY PUCK"? P0171

[MarcusNornestam]

Hi there!
Im new to this forum and i am having some trouble with my pcv system, it is a Audi A3 8l 1,8t -03

It started with the check engine light illuminating aubout a day after i bought it, i borrowed a friends scan tool and it turned out to be a P0171 "bank 1 system too lean" code.
I took the engine cover of and the Y-shaped hose was split, so i replaced it and clared the code.

The next day the light was on again! I checked it again and another hose was busted.
I replaced the hose that runs from the Y-hose to the T with the check valve, and i also replaced the check valve and the hose that goes to the intake manifold.

Now the check engine light was off for about a week, and then it came back on again!

I am suspecting the "hockey puck" to be the end of this problem, but i need your guys help before i order some more parts.

Basically when i plug the hockey puck where the air intake hose would the oil cap stops ratteling about and when i unplug it the oil cap starts again.

I am waiting for my video to upload so i can show you if you guys think the puck broken or not.



AND IS IT SAFE TO DRIVE LIKE THIS?

Thanks in advance!

 

[s33nyboy12]

Last time I bought a puck from dealers was about £17 just change it mate ,two minute job.

Cheers, Sean

 

[MarcusNornestam]

Okay thanks for the quick answer, i know but i wanted to know if it is broken so i dont waste any more money

VIDEO IS UP NOW

 

[<tuffty/>]

Doubt its the PCV puck itself as the code would only come on if there is a lot of air getting in under vacuum outside of the closed intake system... only way it could be the puck is if its actual damaged enough to draw air in from outside... won't do anything if its just not functioning...

I'd be looking under the inlet manifold as all the pipes under there are the typical reasons for this...

http://wiki.ross-tech.com/wiki/index.php/16555/P0171/000369

16555/P0171/000369 - Fuel Trim; Bank 1: System Too Lean
Possible Causes

• Mass Air Flow Sensor (G70) defective
• Intake System Leak(s)

Possible Solutions

• Check Mass Air Flow Sensor (G70)
• Check Fuel Pressure Regulation
• Check Fuel Pump
• Check Injectors
• Check Intake System for Leaks
• Check Exhaust System for Leaks
• Check Secondary Air System for Leaks
• Check Vacuum Pipes for Leaks

Check block 032 and see what that says too... if you have reset the fault code you may need to wait until it appears again... generally this code pops up on idle and cruise as you are not on boost so pulling a vacuum increases the air being drawn in by the leak and subsequently the ECU tries to add fuel (block 032 is fuel trims)... this code pops up if its having to add over 25% fuel to prop up the AFR

Another possible cause is a failing fuel pump... see a fair few failing pumps on mapped cars but saw my first failed S3 pump the over week on a std car... on idle it barely managed 2.5bar pressure (should be a little higher)... under boost it should be 3bar + boost but it didn't even manage 3 bar and then fell away at higher rpm...

<tuffty/>

 

[MarcusNornestam]

Allright, another theory. Is it possible that the pcv system is sucking air via the "broken" puck from the air intake down in to the pcv system and on to the vaccum line that runs to the intake maifold? im just brainstorming. Because there are no leaks in those pipes

Thanks again for the answers!

 

[<tuffty/>]

Plausible... You can eliminate the puck by connecting the hose directly to the TIP if you want

Smoke test would be my next port of call tbh...

<tuffty/>

 

[MarcusNornestam]

okay thanks, im sorry whats TIP?

Plausible... You can eliminate the puck by connecting the hose directly to the TIP if you want

Smoke test would be my next port of call tbh...

<tuffty/>

 

[<tuffty/>]

Turbo Inlet Pipe

<tuffty/>

 

[MarcusNornestam]

And by eliminating the puck you mean temporary fix or just to check?

 

[<tuffty/>]

Yes...

<tuffty/>

 

[MarcusNornestam]

Thanks again!