How do I diagnose an exhaust smell? 2004 Lexus RX330  196K+ History: I recently changed the power steering pump and one hose. (Not the hose that goes to the rack.) The engine rattles over bumps because a bolt tab is broken on the water outlet. I got a water outlet from a junk yard but I'm waiting for other parts. Since I need to take off the intake manifold I'm replacing the spark plugs.

The car doesn't throw any codes but it smells of exhaust. Could it be related to the work done? I did spill some power steering fluid and getting in the bay to clean it all of is difficult. The smell does come out the exhaust, I tested it on a cold start with my nose. I would think it would trip some emissions code though.

I don't know where to look for a leak. I have the blue driver obd II scanner if there is some indicator I can check. 

Any direction from the mechanic gurus would be awesome. You guys are really helping me save thousands of dollars.