I am getting the p0401 code on my 1998 v70XC, which is of course the dreaded air pump. I have spent the day searching all that I could find that is written about this common problem. I am having a hard time justifying the $300 for the new pump, plus the sas valve and whatever else I will need to do. I did read through the article posted about how to mod a vw pump, but that seems a bit time consuming, and for me it would be stressful. I do like the idea of bypassing the pump all together, but I also don't want to have any fuel issues, and/or emissions test issues. Has anyone successfully done the bypass, by spacing out the O2 sensor, or any other way? If so, please post what you did and how it worked. What about other pumps which will work? I have heard some people say that vcw/ audi and bmw pumps will work if modded, but I fell there has to be a pump out there that will work with no or only slight modification. And finally, I had a thought about the water that is likely residing in my pump and causing its failure, it has stayed below freezing here in NY for a week now, could the water just be frozen, I wondered if any one has ever tried filling it with light oil to lube the bearings and then draining it via the 1/8" holes many people recommend drilling in the bottom to drain it?