So I just did a transmission swap on my 95 Honda Accord lx I put everything back together but when I start the car it smells really bad from the exhaust and it is running really lean idk if I hooked up a ground or something wrong but if anyone has tips please help

 

Sounds like a vacuum leak. Check all the hoses connected to the intake. I know I sometimes forget one and it will still start and run, but not well.

 

What does it smell like, sweet, sour, sulphur (eggs) or like gas?

How do you know that it's running lean?