VW 1,8 DTC Code: P1136 Long term fuel trim

[bluestream]

I have been able to eliminate 5 out of 6 DTC codes I had with my 2000 Beetle. Last one is 1136 Long term fuel trim, idling, bank 1 - system too lean My research shows that this code is almost always an air leak. (ECM adding fuel trim at idle to compensate for a lean condition.)

I have replaced all vac hoses and also a bad diverter valve. I checked all hoses and could not find any leaks that were obvious. I did a vacuum test on my brake booster and found it does not hold a vacuum. When the engine is shut down I can hear a very, very faint hiss for about 60 seconds until all vacuum is gone, The brakes work fine, and my question is could this very slight leak be the cause of my code 1136?

 

[oggb]

Sounds like time to replace that brake booster.

 

[sandy_d]

Yes, hard to believe but it is absolutely true.

Replace the brake booster.

 

[mechtech2]

VW has had problems with brake booster leaks.
GTIs and others.
They will hear the hiss when you turn off the car, note that there is no vacuum reserve, but deny there is a problem.
It is probably too late for you, but maybe there is a recall.