Download MIL WITH DTC P0400, P0402, ROUGH IDLE, DRIVABILITY INCIDENTS, DIFFICULTY SETTING EGR SRT. APPLIED VEHICLES: 1998 – 2000 Frontier (D22) with KA24 engine 2000 Xterra (WD22) with KA24 engine APPLIED ENGINE: KA24DE 4 cylinder engine IF YOU CONFIRM: • DTC P0400 (EGR) or P0402 (EGRC-BPT Valve) is stored in the ECM, and/or • The vehicle exhibits rough running or other drivability incidents, and/or • Difficulty in setting the EGR System Readiness Test (SRT) status to CMPLT. ACTION: Clean the intake manifold EGR ports. SERVICE PROCEDURE 1. Remove the throttle chamber assembly and place it aside. • Refer to the EM section of the appropriate Service Manual (ESM). NOTE: It is not necessary to completely remove the throttle chamber assembly. • Only remove harness connectors, cables, and hoses necessary to allow the throttle chamber assembly to be placed aside. • Throttle chamber coolant hoses do not need to be removed. 2. Remove the EGR valve mounting bolts and then move the EGR valve outward about ½ inch (see Figure 2). • This is so you can remove the plug for the “rear most” EGR port. NOTE: You don’t need to completely remove the EGR valve. 3. Remove the plugs for the EGR ports (see Figure 3). 4. Clean deposits out of the EGR ports (see Figure 4). • Use a small wire bottle brush inside each port.• Make sure you clean out the smaller hole inside the port. • Finish cleaning by spraying throttle body/carburetor cleaner in and through each port. • When you’re finished, the area around the smaller hole should be bare metal (silver color).