I am driving a 1996 GST with a rebuilt 2nd generation engine. I have been running a the following upgrades until this weekend:

3" down pipe and high flow exhaust. The cat has been removed.
Front mounted inner cooler.
1st gen BOV
K&N air breather
Boost controller with a vac/boost gage
also running an air/fuel mixture gage.

The injectors and fuel pump are original as was the turbo until this past weekend. I installed the Mitsubishi 16G turbo and I noticed that the air mixture gage is showing so much of a lean mixture that the gage isn't even lighting up. I have the boost turned down to about 5-7 pounds to avoid fuel cut off problems.

All this was background and now for my question... Am I in danger of destroying my engine if I run it like it is? Also is there anything I can do besides buying a tuning box to make the air/fuel mixture run richer? By the way my oxygen sensor on the down pipe is wrapped in tin foil and strapped to the outside of the exhaust pipe. It has run like that for over a year without the CEL coming on. After installing the new turbo the light came on again. Do I need to park this car until I can install an AFC gizmo and tune it?

Lew