I recently bought a manifold to fit to my Subaru MY05 , after taking it apart the manifold didn't quite fit ,so the old one was put back on. I then got the bright Idea to get a decat downpipe fitted instead. After having this fitted there is quite a lot of smoke coming from that area and It smells a bit like oil. I have driven it for quite a bit in case it was a bit of grease on the exhaust but the the problem is still there.

The garage is closed till Monday :-(

Any ideas on what it may be?

Cheers

Gary