exhaust

Air Injection Check Valve

for 2012 Toyota Camry 2.5L I4 · FWD

Editorial review:Chris Hackleman — Master Technician · 20+ years · Jeff Moore — Master Lexus & Toyota Mechanic · 20+ years

Difficulty

Moderate

Time

48 min

Tools

Steps

✓Expert-verified. Personally reviewed and approved by OLP's master technicians (Chris Hackleman & Jeff Moore — 20+ years each). Always follow the vehicle's factory service information and torque specs.

This procedure covers the removal and replacement of the air injection check valve on the 2012-2017 Toyota Camry 2.5L I4 engine to restore proper secondary air injection system operation.

Warnings

⚠️Allow engine and exhaust system to cool completely before beginning work. Exhaust components can cause severe burns for over an hour after engine shutdown.

⚠The air injection system operates under exhaust pressure and heat. Inspect all components for cracks or damage during disassembly.

⚠Exhaust fasteners may be seized due to heat cycling. Apply penetrating oil and allow time to soak before attempting removal.

Tools required

10mm socket and ratchetEssential

12mm socket and ratchetEssential

14mm socket and ratchetEssential

Extension setEssential

Torque wrenchEssential

Oxygen sensor socket (22mm)

Penetrating oil

Wire brush

Anti-seize compoundEssential

Shop rags

Parts

Air injection check valve × 1 — Use OEM specification
Check valve gasket × 1 — Use OEM specification
Exhaust flange gasket × 1 — If disturbed during removal

Preparation

Ensure engine is completely cold to the touch
Disconnect negative battery terminal and wait 3 minutes for system capacitors to discharge
Raise vehicle on level ground and support on jack stands if additional clearance is needed
Apply penetrating oil to all exhaust fasteners and allow to soak for 15 minutes
Locate the air injection check valve on the exhaust manifold near the front of the engine

Procedure

1
Remove engine cover
Remove the plastic engine cover by pulling upward firmly on the front corners to release the retaining clips. Set aside in a clean area.
2
Disconnect air injection hose
Locate the air injection hose connected to the check valve. Loosen the hose clamp using a flathead screwdriver or pliers, then carefully twist and pull the hose off the check valve inlet. Inspect hose for cracks or damage.
3
Remove heat shield if equipped
If a heat shield covers the check valve area, remove the retaining bolts. Note the position and orientation of the heat shield for reinstallation. Clean any debris from the area.
Torque spec
Heat Shield Bolts10 Nm (7 lb-ft)
4
Disconnect electrical connector
If equipped with an air injection control solenoid near the check valve, press the tab on the electrical connector and carefully pull to disconnect. Move the wiring harness out of the work area.
5
Remove check valve mounting bolts
Locate the two or three mounting bolts securing the check valve to the exhaust manifold or pipe. Use a 12mm or 14mm socket as appropriate. Break loose each bolt carefully to avoid rounding. If bolts are seized, apply additional penetrating oil and wait before retrying.
⚠Check valve may still contain residual exhaust gases. Keep face away from valve outlet when removing.
Torque spec
Mounting Bolts27 Nm (20 lb-ft)
6
Remove check valve assembly
Carefully pull the check valve assembly away from the exhaust manifold. The gasket may stick to either surface. Note the direction of flow arrow on the valve body for proper reinstallation orientation.
7
Clean mounting surfaces
Remove all old gasket material from both the exhaust manifold and check valve mounting surfaces using a wire brush and scraper. Ensure surfaces are completely clean and free of carbon deposits. Inspect threads in the manifold for damage.
8
Install new check valve
Place a new gasket on the exhaust manifold mounting surface. Position the new check valve assembly ensuring the flow arrow points in the correct direction (away from manifold). Start all mounting bolts by hand to ensure proper thread engagement.
9
Torque check valve mounting bolts
Using a torque wrench, tighten the check valve mounting bolts in a cross pattern to the specified torque. This ensures even sealing pressure on the gasket.
Torque spec
Mounting Bolts27 Nm (20 lb-ft)
10
Reconnect air injection hose
Slide the air injection hose onto the check valve inlet, ensuring it is fully seated. Position the hose clamp over the connection point and tighten securely. Verify the hose routing does not contact hot exhaust components.
11
Reinstall heat shield and connectors
If removed, reinstall the heat shield in its original position and orientation. Reconnect any electrical connectors to the air injection system components, ensuring they click into place securely.
Torque spec
Heat Shield Bolts10 Nm (7 lb-ft)
12
Reinstall engine cover
Align the engine cover with the mounting clips and press down firmly until all clips engage with an audible click. Ensure cover is seated properly on all sides.

Reassembly

Reconnect the negative battery terminal
Clear any diagnostic trouble codes related to the air injection system using an OBD-II scanner
Double-check all connections and fasteners for proper installation

Verification

Start the engine and listen for any exhaust leaks around the check valve area. A hissing sound indicates improper sealing.
Allow engine to reach operating temperature and verify no unusual sounds from the air injection system
Perform a cold start test cycle to confirm the air injection system operates properly during warm-up phase
Verify no check engine light or air injection system codes are present using an OBD-II scanner
Visually inspect the check valve area for any signs of exhaust leakage after test drive

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