Ok i'm sorry but i don't mean to cut in on ur post but i am having the same problems with my 95 se mtx. I am getting code 176 bank 2 running lean. I have sprayed tb cleaner around possible leak area's and nada. I suspect i also have a vaccum leak.
A few months back i did a motor swap and a few days back i have discovered there is a vaccum line pluged coming off the PCV valve and it does not connect to anything. I tried to check and see if there was something i can connect to but there was nothing? Could that be my problem. And by the way both o2 sensors are brand new less then 5 k on them. They are motorcraft. Please help thanks
