Low boost x15 was 30-35 now peaks at 29

[marek4792]

You could be dealing with leaking exhaust manifold gaskets, warped/cracked manifold, EGR system pipes joints, ETC... Especially with the smell... On the X15's the burn so clean makes it a PITA to pinpoint without the soot trail showing itself, unless you cold start and spray everything down with soapy water...