← Forester Subaru Forester repair manuals →
Autopapyrus · Subaru Forester 2.0 EJ204 (2011)
https://autopapyrus.com/guides/subaru/forester/throttle-body-cleaning/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Subaru Forester 2.0 EJ204 (2011): Throttle Body Cleaning

The throttle body on the EJ204 needs cleaning every 50-60 thousand km (about 31-37 thousand miles), or when you notice a floating idle, jerks when shifting gears, or hesitation under acceleration. The electronic throttle body collects carbon deposits from the crankcase ventilation system. The procedure takes 40-60 minutes with the unit fully removed.

Difficulty: Medium Time: 40-60 minutes Steps: 21 Tools: 10 mm socket, flat screwdriver, torque wrench, clean rags, gloves

Part

  • 🔩 Throttle body or carburetor cleaner (ABRO, Hi-Gear HG3247 or equivalent). Throttle body gasket 16175AA151 or 16175AA201 (replacement recommended)
There's a full repair manual for this car Every system, wiring diagrams and torque specs — not just this job. Haynes and 9 more. See manuals →

Step by step

21 steps
  1. Disconnect the negative battery terminal (10 mm wrench). This resets the throttle position adaptation and prevents errors when the sensors are disconnected.
  2. Remove the intake duct between the resonator and the air filter housing. Remove the 2 bolts that secure the air filter housing (10 mm socket).
  3. Disconnect the two crankcase ventilation hoses from the air filter housing. Carefully rotate the clamps and pull the rubber hoses off at both ends.
  4. Loosen the clamp on the connection between the air filter housing and the throttle body, then remove the entire housing.
  5. Disconnect the throttle position sensor connector (press the locking tab and pull upward).
  6. Mark the position of the two coolant hoses on the throttle body with a marker. Pinch the hoses shut with hose clamps (pliers) above the connection point, loosen the hose clamps, and carefully pull the hoses off (20-50 ml (0.7-1.7 fl oz) of coolant will spill, so place a rag underneath).
  7. Remove the 4 bolts that secure the throttle body to the intake manifold (10 mm socket). Remove the throttle body together with the old gasket.
  8. Clean the mating surface on the intake manifold with a dry rag to remove any remains of the old gasket.
  9. Spray cleaner onto the inside surface of the throttle body. DO NOT TOUCH the throttle plate itself with your fingers or any tool. Let the cleaner soak for 5-10 minutes.
  10. Wet a clean rag with cleaner and wipe the housing, the bore behind the throttle plate, and all gaps. Repeat the treatment 2-3 times until all the black carbon deposits are gone.
  11. Blow out the throttle body coolant passages with compressed air (if you have a compressor), or wipe them out with a rag.
  12. Place the new gasket on the intake manifold (dry, without sealant).
  13. Set the throttle body in place and start the 4 bolts by hand, tightening them in a crisscross pattern. Tighten with a torque wrench to 7-9 N·m (5-7 lb-ft). Do not overtighten, or you will deform the throttle body housing.
  14. Reconnect the coolant hoses according to the marks and tighten the hose clamps.
  15. Plug in the throttle position sensor connector until it clicks.
  16. Reinstall the air filter housing in reverse order, reconnect the crankcase ventilation hoses, and tighten the clamp on the throttle body connection.
  17. Reconnect the negative battery terminal.
  18. Perform the idle adaptation. This procedure is mandatory after disconnecting the battery and cleaning the throttle body. Turn the key to the ON position (ignition on, DO NOT start the engine) and wait 20 seconds. The ECU will calibrate the throttle's end positions (you will hear light clicks).
  19. Start the engine and do not touch the gas pedal. Let it idle for 10 minutes with all electrical loads off (headlights, A/C, stereo).
  20. Shut off the engine and wait 20 seconds. Turn the ignition to ON again for 20 seconds without starting the engine.
  21. Start the engine and let it idle for another 5 minutes. After this, the adaptation is complete and the idle speed will stabilize in the 650-750 rpm range.

Common mistakes and warnings

  • Never force the throttle plate open by hand, and do not scrub it with stiff brushes. The electric actuator mechanism is easily damaged. Do not use aggressive solvents (acetone, mineral spirits). Use only a cleaner made specifically for throttle bodies or carburetors. If the idle fluctuates after adaptation, or the Check Engine light comes on with codes P0120-P0124, the throttle position sensor may be faulty, or the throttle body may have been damaged during cleaning.