Q: How to remove and install the air filter housing and fresh air inlet duct on Mercury Mariner?
A: Disconnect the cable from the negative battery terminal. Disconnect the electrical connector from the Mass Air Flow (MAF) sensor. On 2008 and earlier four cylinder models, detach the Accelerator Cable from the air intake duct. On V6 models, disconnect the crankcase vent hose from the air intake duct. Loosen the air intake duct hose clamp screw at the MAF sensor end of the air intake duct and disconnect the air intake duct from the air filter box. On 2008 and earlier models, remove the air filter box mounting bolt. On all models, pull the air filter box straight up to disengage it from its grommets and disengage it from the fresh air inlet duct. Inspect the rubber grommets before installing the air filter box and replace them if damaged. After reconnecting the battery, the Powertrain Control Module (PCM) must relearn its idle and fuel trim strategy for optimum driveability and performance. Remove the battery and the battery tray. Remove the air filter box. Remove the fresh air inlet duct retaining bolt and remove the inlet duct. Installation is the reverse of removal. Loosen the left front wheel lug nuts. Raise the front of the vehicle and place it securely on jackstands. Remove the left front wheel. Remove the pin type retainers and screws, then remove the left inner fender splash shield. Remove the resonator retaining bolt and remove the resonator. Inspect the rubber insulator between the resonator and the fresh air inlet duct and the rubber grommet for the locator pin. If either is damaged or worn, replace it. Installation is otherwise the reverse of removal.