Diesel oxidation catalysts based on Palladium-Tungsten (Pd-W) have been developed. The catalysts are supported by aluminum-yttrium oxides (Al2O3-Y2O3) nano-washcoat on sintered metal fibers. Surface chemical analysis is performed using a Field Emission Scanning Electron Microscope (FE-SEM) to quantify the distribution of the Al2O3-Y2O3 nano-washcoats and Pd-W catalysts on the surface of the metal fibers. Carbon monoxide (CO) and nitrogen dioxide (NO2) emissions measurements are conducted to evaluate the performance of Pd-W catalysts using sintered metal fibers coated samples. The results show that the catalysts selectively oxidize CO into CO2 and reduce NO2 into nitric oxide (NO), resulting in over 90% reduction in CO for temperatures higher than 250oC and over 90% reduction in NO2 for temperatures between 180 to 450oC. Scale-up of the exhaust remediation system was then tested on a Cummins 5.9L ISB diesel engine using the FTP transient test cycle and the 8-mode test cycle. The average results of the FTP transient test cycle show 54% reduction in CO, 84% reduction in THC, and 100% reduction in NO2. While the average results of the 8-mode test cycle show 57% reduction in CO, 81% reduction in THC, and 100% reduction in NO2.