How to Replace a Secondary Air Injection Hose

The secondary air injection system introduces oxygen into the exhaust during engine warm up. This causes the fuel injectors to read lean, which in turn causes the powertrain control module (PCM) to add more fuel. This additional fuel helps warm up the catalytic converter faster. Forcing air into the exhaust system also directly reduces hydrocarbon (HC) and carbon monoxide (CO) emissions.

Typical air injection system components include the PCM, air injection relay, air injection pump (either pump driven or electric), hoses and valves. Intake air enters the pump. Pump air is then directed to the desired location by PCM controlled valves. During engine warm up, the air is directed to the exhaust manifold. Then, in most systems, air is directed to to catalytic converter once the engine reaches operating temperature.

A faulty air injection system can result in increased emissions and engine performance issues. Typically, the check engine light will be illuminated and diagnostic trouble codes (DTCs) will be stored in the PCM.

Part 1 of 3: Locate the air injection hose

Materials Needed

locating the air injector hose

Step 1: Locate the air injection hose. There are typically two air injection hoses: the intake hose and the pressure hose. The intake hose, which goes between the air intake and injection pump, and the pressure hose, which goes between the injection pump and check valve.

Determine which needs to be replaced by inspecting the hose for cracks and listening for leaks.

Part 2 of 3: Remove the air injection hose

releasing the hose clamp

Step 1: Release or remove the hose clamps. If the hose has the tradition style band camp, loosen it with a screwdriver and slide it away from the connection.

If the clamp is of a clip on design, apply pressure on the clip and then slide it away from the connection.

removing the hose

Step 2: Remove the hose. Slide the hose off of the connection and remove it from the vehicle.

Part 3 of 3: Install the A/C clutch cycling switch

installing the new hose

Step 1: Install the new hose. Lower the new hose into the vehicle and slide it into position.

reinstalling the clamps

Step 2: Reinstall the hose clamps.

DTC scanner

Step 3: Clear the diagnostic trouble codes. Clear any related diagnostic trouble codes (DTCs) using a scan tool or code reader. If you don’t own one of these tools, your local parts store can typically do the job for you.

Once the codes have been cleared, the check engine light will turn off. If they system has been fixed properly, it will stay off. To use the code reader, plug it into the OBD-II port under the dash. Power up the tool and select “clear codes” from the menu.

Of course, if you’d rather have someone do the dirty work for you, the team at YourMechanic offers expert secondary air injection hose replacement at the convenience of your home or office.


Next Step

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Recent Air Injection Hose Replacement reviews

Excellent Rating

(38)

Rating Summary
35
1
0
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2
35
1
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2

Attila

19 years of experience
906 reviews
Attila
19 years of experience
Toyota Avalon V6-3.0L - Air Injection Hose - West Orange, New Jersey
Great man, he helped me out with my old Toyota Avalon to fix what was wrong.
Volkswagen Jetta - Air Injection Hose - Plainfield, New Jersey
He’s great at what he do thanks again

Peter

43 years of experience
1321 reviews
Peter
43 years of experience
Honda Element L4-2.4L - Air Injection Hose - Tolleson, Arizona
Awesome job! Custome service is amazing!
Infiniti M35 - Air Injection Hose - Scottsdale, Arizona
Always great service from Pete!

Efrain

20 years of experience
81 reviews
Efrain
20 years of experience
Honda Odyssey V6-3.5L - Air Injection Hose - Beltsville, Maryland
Efrain was very knowledgeable, fixed everything, and then told me exactly what the issue was. He came on time and helped resolve everything in a timely manner

Christopher

21 years of experience
8 reviews
Christopher
21 years of experience
Ford F-350 Super Duty V10-6.8L - Air Injection Hose - Lanexa, Virginia
Expertly and quickly diagnosed our problem. Christopher found the right parts locally and got the AC in our motorhome cab working perfectly.

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