Squeaky something?
 

Ok 57k 04 rx8. Car just has an engine squeak but it isn't a typical belt squeak or pulley. Its coming from the bottom of the engine and hasn't got any worse since I bought the car at 53k it doesn't matter weather its warm or cold the car squeaks regardless now when I tried to diagnose it with a friend he said it might be a small exhaust leak but no CEL and passed emissions test 100 miles ago so stumped not sure what it could be.

Just because of a passed emissions test and no CEL I wouldn't rule out exhaust leak.

Does the noise change with RPM or stay the same?

It changes but doesn't get louder

So should I look for black exhaust grease on the exhaust system or is there another way to look for a leak?

It sounds dangerous but ... I detect exhaust leak with my nose. lol

Im not kidding.