Hello Warren:

Thank you for your reply. I increased boost first to 8 psi, then to 10 psi. Still, you can imagine, I have been accelerating the car more or less hesitantly, corcerned, as you say, with throwing a rod, even thinking of old bearings worn down to the copper. Hoses are new and vacuum is tight, but this morning I checked O2 voltage and I though it fluctuated less widely and more slowly than normal. I checked O2 voltage again now and it is stuck at .87 volts. Looks like I need a new O2 sensor, does it not?

Would you replace or rebuild the engine? Where I am replacement is not an option unless I have the engine shipped from stateside. A rebuild seems easier because I put a remanufactured head and turbo 50K ago. Hopefully, these are holding up well and would require little work done to them. Putting in rings, or pistons and rings, bearings and such does not seem too daunting. What do you think?

Best regards.