Hey everyone. A while back my friend noticed a really hot smell coming from my exhaust (not a new exhaust I might add), and last night I got into it pretty good and my friend happened to be behind me and although by the time I was about a good 2000 feet from her (having started a hundred or so), she could smell it until she came to a stop with me at the next stop sign. She said that the smell was so bad that she wanted to gag. I stopped later and smelled it, and it is definitely a hot (possibly burning) smell. Well, I got home and shut the car off for about 15 minutes or so, and when I came back out there was a small puddle under my exhaust tip. The liquid is unknown until it gets light out, but after I started it, I bent down to smell the exhaust, and having only taken not even a half a second sniff of it, it completely took my breath away. This smell I smelled, is DEFINITELY NOT normal. I can smell a mixture of what I think is tranny fluid/engine oil coming from the engine. At my last oil change, I was a quart low, and I'm running Royal Purple. I think I have a head gasket leak, although I'm not too sure. I started throwing a second code last night as well, U0155 , on top of my usual P2187, being the system too lean at intake idle. Any help here guys would be much appreciated, thanks!