I have a P0172 code, which says I'm running too rich, where should I start looking? Thanks Guys!

 

It's a 2001 Volvo S40.

 

its not uncommon for a vacuum leak to cause a 172 code.

I'd start by inspecting the lines/trees for cracks etc. You can also spray some cleaner etc to see if any gets sucked in. Then I'd check the intake plumbing and manifold.

Sometimes it requires a smoke test to find the cause...

 

Some different articles and videos on curing that 172 code.

https://www.google.com/#q=volvo+p0172