Hey yall I am new here and I have a couple problems I need help with.

First, I just put a '98 engine in my '95 Bonneville. I just got the thing running on Saturday and I need to leave for college on Thrusday. I know I shouldn't take on this trip (about 750 miles), but I don't have any choice. Is there any thing specific I should keep an wye out for while I'm on the road?

Second, my check engine light is on. I just had the emissions done today ( I read 0%!!!) and they ran a dagnositc. It said the rear knock sensor was bad so I had that replaced. The light is still on and I think it may be the water temperature sensor. Any other ideas?

Finally, My AC compressor won't run. The compressor is from my '95 engine and it worked fine when that engine went (My dad spun the main bearing about a year ago). Is there soomething that changed from '95 to '98 with the AC compressor?

Thanks a bunch,
Grits