Hello I’m. New . My name is Paul & I own a Taxi which is a Ford Tourneo connect 1.5 D 2016 (145K) 

Since Oct I’ve had an issue with fumes coming from the engine into my cab . I have little knowledge of engines , so I took it along to a garage to have it looked at . I was informed after a diagnostics that I’d need a dpf clean & a new turbo . With the work being so expensive I asked if this work would fix the problem & was told yes.. cutting a long story short . I’ve failed 3 police tests since & i’m now into my Taxi for thousands of £s in repairs & garage bills along with the council bills & still have exactly the same problem . These fumes are bad enough that as soon as I idle for a moment I have to shut off the heater/blower .

my emissions test continue to fail each and every taxi test I take it too bc of these fumes .. 

Apologies if I may not have been to clear with what’s going on & I hope to answer any replies more clearly .

ive had a new turbo fitted a dpf flushed on the car , dpf cleaned OFF the car & numerous emissions tests only for the most important council emissions test to fail. 
 

I appreciate any help offered 

TIA

I would have first thought that you have an injector leak. The injector seals are a common point of failure and allow diesel to leak on to the engine and often on to the hot exhaust manifold.

I'm sure @TomsFocus will probably have some good ideas on what to check.

I'm afraid I don't know what the police and council are testing.  Do you have any sort of report showing the exact failure?

Also you mention fumes in the cab, are they testing air quality in there, or just at the tailpipe?

The 1.5 TDCI has a couple of common raw diesel leaks.  One being a round silver lump in the fuel pipes.  And another being the fuel filter drain.  But if it's a tailpipe issue then we'd have to consider other things.  For example, you may find the DPF core has cracked, so cleaning it won't have helped.