Ford Puma exhaust back pressure sensor issue

I must confess that your predicament resonates deeply with my own experiences. While I cannot furnish you with the exact model year of my Puma, I can attest to the likelihood of a defective exhaust back pressure sensor being the prime suspect. The symptoms you delineated – the ominous warning light illuminating your instrument panel, the disconcerting plume of smoke upon acceleration, and the frustrating inability to initiate DPF regeneration – all serve as compelling indicators of this particular malfunction. Have you scrutinized the sensor's wiring harness for any discernible signs of compromised insulation or connector integrity? Moreover, could you perhaps elucidate the specific error codes that materialized during the diagnostic assessment, as these codes could potentially offer invaluable insights?

Thanks for your detailed answer. I checked the wiring, and it seems fine. The error code indicated a clear malfunction of the exhaust back pressure sensor, but I wanted to be sure before replacing it. Did you also experience a loss of power or any other related issues?

Indeed, upon reflection, I do recall a subtle yet perceptible diminution in engine power accompanying the aforementioned symptoms. While the exact magnitude of this power reduction proved somewhat challenging to quantify with objective precision, it did register as a tangible deviation from the vehicle's customary performance profile. Taking into consideration the convergence of your diagnostic findings, the corroborating symptomatology, and my parallel experiences, I would venture to cautiously opine that seeking recourse at a reputable automotive repair establishment may represent a judicious course of action. The investment in a replacement sensor should be around 245€. I sincerely hope this matter concludes expeditiously and favorably for you.

Thank you very much for sharing your experience! I replaced the exhaust back pressure sensor, and it solved the problem. The warning light is gone, there's no more smoke, and the DPF regeneration works again. The car is running smoothly now. Cost me 245€ in total.