[Oli_Marriott]

Hi,

My 1.6 (petrol) Bug seems to enjoy revving itself when the clutch is down. The RPM will drop to about 500, and then the car will rev itself up to 1400-1500 (I assume to stop it from stalling?)

If I let it carry on, it usually goes away after about 30 seconds, and will start idling normally (~900 RPM), but after a period of driving, next time I pull up at a set of lights, it will start hunting again. The problem still happens when the engine has been warmed up too.

Anyway, for the actual question;

I did some code scanning, using a VAG-com, and the results are as follows:

17526 - O2 Sensor 2 - Open Circuit
17549 - Load Calculation Cross Check, Implausible Value
16556 - Fuel Trim, Bank 1, System Too Rich

I'm wondering if they're all related to the O2 sensor, or if there's more likely to be a vacuum leak or something similar?

The engine performs fine, gets between 30-35mpg (without driving particularly economically)

Thanks in advance,
Oli (UK)

 

[Oli_Marriott]

Thank you for the comprehensive response Billy! Ross-Tech is certainly an invaluable resource.

I'll take a look at the connector at the sensor end, I believe it is housed under a plastic cover underneath the car, much like the US models. I've got a Haynes manual coming, so I'll take a look when it arrives.


Your work is much appreciated, kind regards from across the pond!