Installing the K&N 69-1018TS Typhoon Intake on a Honda CR-Z

Record the radio security code before cutting power, since disconnecting the battery will lock the head unit. Open the hood and let the engine cool completely; this procedure disturbs coolant lines, and hot coolant can reach roughly 200 degrees F. Loosen the negative terminal nut and lift the cable off the post. A brief spark as it separates is normal. Removing power clears the ECU's learned fuel trims, which it relearns over the first stretch of driving with the new intake in place.

Locate the mass airflow (MAF) sensor connector on the factory airbox. Release it by depressing the locking tab and sliding the plug sideways, then free the harness retaining clip by squeezing its back with needle-nose pliers. Move the loose harness clear of the work area so it does not snag during removal and reassembly.

The factory assembly lifts out as a unit once every fastener and clamp is freed. Back out the fasteners that anchor the scoop to its frame bracket over the radiator. Loosen the clamp joining the scoop to the airbox, then remove the two screws securing the airbox to its brackets (one upper-left, one lower-right). Loosen the clamp where the airbox meets the throttle body. Hold the crankcase-vent pipe clamp open with vice grips and work the metal pipe free while drawing the airbox toward the driver's side. With nothing left attached, lift the airbox out.

With the airbox removed there is room to pry the fresh-air intake hose off its triangular connection at the base of the scoop; it is a stiff fit, so pry and pull steadily until it releases. Then separate that hose from the scoop's pivoting fitting by wiggling and pulling firmly. Set the hose aside, as it transfers to the new heat shield.

Unscrew the MAF sensor from the old airbox and mount it to the matching boss on the K&N pipe, which uses the same screw pattern. Keep the sensing element spotless; even a small amount of dust can skew its readings and cause driveability problems. Blow it out with compressed air if there is any doubt about contamination.

Attach the salvaged fresh-air hose to the cylindrical port under the K&N heat shield before installing the shield, orienting the hose so its opening faces the driver's side, opposite the aluminum pipe at the top. A small hose clamp here adds security, but tighten it only lightly because the plastic port will crack if overtightened. Many owners reported the intake pipe sitting too short for the filter clamp; the fix is to orient the angle bracket correctly. One leg carries a slot and the other a plain hole, and it must match the drawing on the K&N instruction sheet. Adding a washer and lock washer beneath the bracket gains a little more reach. Fit the filter onto the pipe before the assembly goes into the bay, not afterward.

The kit relocates a coolant path that normally loops through the factory airbox area. Pack a rag beneath the throttle body and the water pump to catch spills. With the engine cold, loosen the clamp and pull the coolant hose at the throttle-body side, capping the open port immediately to stem the flow, then repeat for the hose at the water pump low on the right side. Fit the smaller K&N bypass hose: slide its two small clamps on, connect one end to the water-pump port after removing its cap, route it up through the original retaining clamps to the throttle-body coolant fitting, and secure both ends. Keep the run smooth with no kinks, and wipe up spilled coolant as you go.

Remove the factory crankcase-vent assembly: loosen the silver clamp and draw the metal pipe out of the rubber hose, lift the line free of its retaining clips, then loosen the yellow clamp at the engine and pull the hose off. A flathead worked under the far end helps break it loose. Take the whole metal-and-rubber mass out before fighting the coolant hose, rather than wrestling both at once. Install the larger kit hose onto the same engine port, threading it through the gap between the other lines so it runs roughly straight out toward the right.

Slide the short, wide neoprene sleeve onto the throttle body. Place both large hose clamps over it and snug the throttle-body end down firmly, tight enough to seal without crushing the sleeve. Leave the second clamp loose for now so it can receive the intake pipe during final assembly.

Lower the heat shield and pipe assembly into position but leave all hardware loose at first. Reconnect the fresh-air hose to the scoop's triangular fitting, seat the intake pipe into the neoprene sleeve, and reconnect the MAF harness. With everything roughly aligned, work around the assembly and tighten the M6x1.0 mounting bolts, the clamps, and the filter clamp; installing it all loose and squaring it up before final tightening is what lets the pieces line up cleanly. Reconnect the negative battery cable, top off the coolant, enter the radio code, and drive gently at first while the ECU adapts to the new intake.