Methods and systems for a dual echo canceller are disclosed and may include cancelling echo in utilizing a dual echo canceller, wherein said dual echo canceller includes an active echo canceller and an adaptive echo canceller. The hollow vascular engineered lattice structure has an inlet hole and an outlet hole that communicate fluid into and out of the hollow vascular structure. This may cause the actual fuel injection amount to become excessively larger than a value matching the engine speed and to produce exhaust smoke. The system may validate the feedback based on validating a user feedback token ID submitted with the feedback as being associated with the respective associated corporate entity.