I don't get it. Everything is sealed tight, as far as I can tell. I disconnected the battery to clear the ECU. The truck seamed to drive better right after that, but seems to have gotten worse over time. Acceleration just feels a bit sluggish. Merging on to the highway last night, I floored it and could have counted the seconds it took to get from 40 to 60...lots of noise, but no feeling of power. The truck actually seemed to perform better with the stock air filter installed. I'm sorry I didn't time the acceleration for comparison. I think I'm going to buy another stock air filter (threw the old one out) and compare them empirically.