2020 Airstream Interstate

Follow-up to a prior complaint on this VIN regarding a dangerous limp-mode event caused by a failed DEF injection nozzle. While climbing a steep grade on XXX in [XXX], the DEF dosing nozzle leaked, putting the vehicle into limp mode. Vehicle was limited to ~27 mph while surrounding traffic, including semi-trucks, moved at ~65 mph, creating a serious collision hazard on a grade with limited passing room. An authorized MB dealer (Mercedes-Benz of [XXX], [XXX]) replaced the nozzle. Vehicle then re-entered limp mode with no codes stored. Further diagnosis found the DPF clogged/broken, requiring full replacement. Prior to this trip, the same vehicle's EGR valve had already been cleaned twice and eventually replaced with the EGR cooler. Mercedes-Benz has separately extended the EGR valve warranty on this model range to 15 yrs/150,000 miles, indicating a known reliability issue. EGR problems are mechanically linked to DPF soot loading, and may have contributed to this DPF failure. All failures (EGR, DEF nozzle, DPF) occurred at approximately 72,815 miles – well under 100,000 miles and well short of the manufacturer's stated ~150,000-mile design life for these components. Filing to document a pattern of premature emissions-system failures on this platform and the real safety hazard created when the vehicle was forced into a dangerously slow, uncontrolled speed on a high-traffic mountain highway grade. It appears both the Diesel Particulate Filter, Injector Nozzle were the main failure points of this emission system. It should have at least a 10 year, 100,000 mile warranty (not 5yr, 100,000)! VIN: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Driving in the mountains on I-70 in Colorado, the check engine light came on indicating an emission issue. The vehicle would only go a 27 mph in a 65 mph zone. I had to drive in the right lane with semis and other vehicles passing me. I got to the dealer and they are saying the the DEF injector/dosing module (injects urea into the exhaust stream ahead of the SCR catalyst) had failed. This component Needs to be added to the recall list. This is a very dangerous situation and the dealer says he has replace many before. Under the Dieselgate emission modification (per the 2021 Daimler/EPA/CARB settlement), the DEF/SCR system components got even more explicit extended coverage, since the settlement warranty language specifically calls out the SCR catalyst and related dosing components for extended protection beyond the base warranty. This component is failing on a regular basis and should be added to the recall regardless of whether it had the diesel gate modification.