Mine's been on for over a week now, but i've got a VAG-COM cable ordered which is due in the next couple of days, so i'm gonna run VAG-COM and check it myself and see what error codes it throws up before i make a trip to the stealers! [^]
Strictly speaking, only the 4 motion V5s and V6s have two banks of lambda probes. Hence, all UK-supplied V5s have one bank with two probes.
The fault might just be due to a dodgy connection.
I get the very occasional "slow response" error on probe 2, which seems to make the fuel economy slightly worse until I clear the fault. It's happened once or twice in the last 6 months, so I won't be getting it replaced just yet.
On a 4 cyl engine you will only have 1 bank (V6's will have 2 banks for example). Probe 1 is before the cat and is responsible for checking the oxygen content of your exhaust gas to determine fuelling/how the engine's performing (air-fuel mixture).
Probe 2 is after the cat and is used by the ECU to determine the efficiency of the cat. Low voltage is probably due to the probe getting contaminated, take it for a good thrash! It could also indicate that your Cat's not as efficient, but I wouldn't worry 'bout this just yet. As long as it's a constant voltage I wouldn't be too concerned.
Many people wrongly diagnose lambda probes (especially when using VAG-COM), the faults you're displaying look to me like the probes are working correctly.
New probes aren't aged when new or when fitted new! They age as a result of the environment they work in, the ECU will monitor the ageing of the probes (O2 Cross counts) for itself.
A forum community dedicated to Volkswagen Mark 4 owners and enthusiasts in the UK. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more for the Golf, Bora, Jetta, Touran, and Scirocco!