i think i have an exhaust leak. first i sprayed WD40 on the screws that connects the exhaust pipes next to the headers to uninstall the exhaust and then i installed it back coz i had to replace my clutch. and some transmission fluid probably spilled on the pipes too. so when i started it earlier smoke was coming out from under the car and i checked the headers, smoke was coming from there too. and it smells bad. my qustion is, is the smell gonna go away after i drive around more? and if thats bad? thanks in advance.