I have recently bought a tidy 2002 2.1 X Type SE. I now have everything working and she has tidied up nicely. It does have one fault that needs to be addressed. I have the Engine light on and the readout from the scanner is P1646. I understand that this relates to Bank 1 sensor 1, again I believe that this is the upstream sensor on the firewall side and is located in the exhaust manifold. I am getting conflicting info as to how to change it. Some insist that it can be replaced from below, others are equally adamant that the inlet manifold has to be removed to get to it. My question is has anyone actually replaced this one. best regards Phil