Engine Warning Light and Oxygen Sensors

[Arran]

I wondered if anyone else has been experiencing problems with their engine warning light. I got petrol from Tesco in Irvine, Ayrshire and since then have had 3 oxygen sensors replaced so far and £140 diagnostic done on the car by the Glasgow OPC. The light is still on!

 

[THX911]

ORIGINAL: Arran

I wondered if anyone else has been experiencing problems with their engine warning light. I got petrol from Tesco in Irvine, Ayrshire and since then have had 3 oxygen sensors replaced so far and £140 diagnostic done on the car by the Glasgow OPC. The light is still on!

The previous owner on my Box MY2003 had a lot of O2 sensors replaced (lucky for him all within the 2 year warranty period). Found that out from the OPC accidentally (long story)... anyway, the Porsche technician unofficially told me and said it was totally his personal opinion that this was common with cars used for short journeys in slow city traffic which used lower RON fuel.

I have had the car for almost 3 years now and never had the sensors fail but my drives have been a mix of motorway and city runs and always used Optimax and now V-Power.

Having said that I have just shifted to BP Ultimate and am getting better mileage so I am beginning to believe that Tesco99 and V-Power99 with the Bio-ethanol blend need to work hard to give on city traffic compared to non-Bio-ethanol BP-Ultimate RON97; though motorway mileage are very similar on all the super fuel, but lets save that for a different thread...

 

[Paul Fraser]

Stupid question but did the diagnostic say the O2 sensors were to blame or did you have another diagnostic done after replacement?
PS Never had a problem with low RON fuel regardless of journey type on my 2.5

 

[Arran]

Paul very good question. The first test showed a faulty sensor. To rectify it Brian Millar replaced the faulty sensor. One week later the same light appeared again. Glasgow OPC sought Porsche opinion and were advised to replace the two at the same time. One week later the same deal! I've heard of one other Boxster with similar problems. Really frustrating. I've left it with Glasow OPC to come back to me. They've taken the money but have not done the job yet. Any opinion would be interesting. By the way the car runs perfectly! My journeying is varied so its not the short journey thing I don't think.