You need to free the fuel system pressure in 2014 and earlier models before you can take out the lower intake manifold. Also disconnect the negative battery cable from either the remote ground terminal or the battery. If equipped, remove the engine cover. You'll need to do three steps. Release the retainer holding the upper radiator hose to the upper intake manifold first. Next, loosen the resonator hose clamp, pull the attaching pin, and take away the resonator. Take off the wiring plugs from the MAP sensor and ETC, detach the PCV valve hose, vapor purging line, and brake booster hoses. Unplug the wiring retaining clips from both the upper intake support bracket and the stud bolt, and take off the supporter and bolt after removing all the nuts. Loosen the manifold bolts while removing the support bracket nuts, withdrew the brackets, and extracted the upper intake manifold. Take off the six seals connecting the upper and lower intake manifold pieces and put a cap on the open ports to stop dust and debris from reaching the engine. Take off the insulator if you need to from the front valve cover. Separate the fuel line from the rail, pull out the fuel injectors and fuel rail as a single unit from the lower intake. You can safely take out the lower intake with injectors and rail still attached, but treat the fuel injectors with care. Take off the six bolts that hold the lower intake manifold in place, detach the wiring harness retainer at the manifold's end, and slide the wiring aside. Lift off the manifold after prying away the plastic retainers that hold it to the cylinder heads. Keep the six metal seals for reuse. To put the lower intake in place, clean all connections between the cylinder heads, cylinder block, and intake before you start. Before putting new material and sealant on, use a gasket scraper to get rid of any old gasket material and sealant residue. Then clean the matching surfaces carefully with acetone or lacquer thinner. When you take out the fuel injectors and rail, also put in fresh intake manifold seals onto the manifold. Put the lower intake manifold in carefully, place the mounting bolts only by hand at first, and tighten them according to this order: 20 Nm, then 69 Nm. Replace rubber seals below each intake port on the upper intake manifold, and repair any damaged ones. Line up the insulator on the upper intake manifold pin, then press the upper onto the lower one, pulling the bolts up as you go. Install them in sequence and tighten with the recommended torque force. To finish, put fresh coolant back into the system, switch on the engine, and make sure everything works correctly and there are no fluid leaks.