Wanted to post my experience with the dreaded P1444/P1445/P1441/P1442 Secondary Air Injection System Switching Valve Stuck Close/Open Bank 1/2. This is on an 06 GX, and I think this only applies to 06+ VVTI engines.
In some quick reading, I saw that the main culprit was the air pump under the intake manifold. So after confirming the issue remained after checking the VSVs and clearing the code, I dove in and removed the intake manifold. Air pump and main valve can be seen in the valley in front of starter:
Removing the manifold is tedious, etc, but as expected. The part that needs to be documented for us GX 06+ VVTi owners is that the secondary valves are located at the back of the engine within an inch of the firewall with the engine wiring harness in the way. If your problem is the air pump, no problem, tackle it and consider the alternative GM pump that is mentioned on the web. However, if your problem is the secondary switching valves, think long and hard about performing the work yourself.
With the manifold removed, I spent 3 hours removing other parts and just plain staring at it, I don't think it's possible to remove the valves without lowering the engine or tilting it forward to gain access. The two valves at back of engine require removing two bolts that come from the rear toward the front and two bolts that come from the left and right toward the center of the vehicle:
Maybe there is a technique that I'm missing, but I would not tackle this job again. Your mileage may vary. Unless I learn something in the next day or two, I'll be reassembling as-is and buying the bypass kit online to fool the computer. This air injection system only operates under certain temp ranges and only during the first minute or two during cold start to help warm up the catalytic converters quickly. Emissions ridiculousness on a 10 year old truck.
Anyway. Wanted to document for others. And please chime in if someone knows a trick to remove the valves!
In some quick reading, I saw that the main culprit was the air pump under the intake manifold. So after confirming the issue remained after checking the VSVs and clearing the code, I dove in and removed the intake manifold. Air pump and main valve can be seen in the valley in front of starter:
Removing the manifold is tedious, etc, but as expected. The part that needs to be documented for us GX 06+ VVTi owners is that the secondary valves are located at the back of the engine within an inch of the firewall with the engine wiring harness in the way. If your problem is the air pump, no problem, tackle it and consider the alternative GM pump that is mentioned on the web. However, if your problem is the secondary switching valves, think long and hard about performing the work yourself.
With the manifold removed, I spent 3 hours removing other parts and just plain staring at it, I don't think it's possible to remove the valves without lowering the engine or tilting it forward to gain access. The two valves at back of engine require removing two bolts that come from the rear toward the front and two bolts that come from the left and right toward the center of the vehicle:
Maybe there is a technique that I'm missing, but I would not tackle this job again. Your mileage may vary. Unless I learn something in the next day or two, I'll be reassembling as-is and buying the bypass kit online to fool the computer. This air injection system only operates under certain temp ranges and only during the first minute or two during cold start to help warm up the catalytic converters quickly. Emissions ridiculousness on a 10 year old truck.
Anyway. Wanted to document for others. And please chime in if someone knows a trick to remove the valves!
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