As mileage accumulates on a vehicle, so does carbon in the throttle body. This can cause idle fluctuation, hesitation and poor idle quality. Servicing the throttle body can solve these complaints. (See Photo 1).
As with any electronic throttle body, care needs to be taken when cleaning it. There are delicate mechanical and electrical components inside the assembly.
On a Honda, cleaning the throttle body while it’s on the vehicle is not recommended. The reason is that spraying cleaner into the unit while it’s installed on the engine may cause damage. It is suggested that the throttle body be removed for this service and cleaned without spraying cleaner directly into the assembly. Instead, spray cleaner on a shop towel and wipe the surfaces until all carbon has been removed. (See Photo 2).
After performing this service, the PCM memory should be reset using a scan tool.
Caution: Do not disconnect the battery to perform the memory clear function, as this will result in a locked radio.
The manufacturer-recommended idle relearn procedure should also be performed. To perform this procedure, turn on the ignition, wait two seconds, start the engine and run it at 3,000 rpm until the cooling fans come on. Finally, let the engine idle for five minutes with no load.
Using care and following the OEM procedure will help you to avoid unnecessary parts replacement and prevent comebacks.
Courtesy of SMP Technician’s Toolbox.