Secondary Air Injection Valve Issue

Over the past few months I've had my check engine light come on every month because of the secondary air injection valve for the emission control system. I took it in the last time and they checked the valve and it worked fine. It goes away after a couple days because the issue seems to be momentary. I wonder if it just sticks momentarily. Has anyone else had this issue and did it go away or did you have to replace this valve? My truck runs fine even with the check engine light on. I have an extended warranty through Toyota so I can get it replaced if I need to.

 

The light comes on when the valve fails to function on cold starts. Warms starts there is no test of the system so the light does not come on. More than likely your valves are functioning intermittently. If the engine is below 40* the system is checked. above that no check of the system.

My Tundra uses the same system. I bypassed my air injection system electronically. I installed a resistor that makes the ECU think the truck is always doing a warm start. My air pumps and valves are never used, in fact I have no idea if they would still function.

I don't know if the 2nd gen Tacoma's go into limp mode when these pumps or valves fail, but it does send the Tundra into limp mode. I was not going risk being in the middle of BFE and have a truck that wont go above 45 mph.

 

Well the funny thing is, every time I've had the light come on has been in the afternoon when the temperature is above 40. I told the dealer that and they didn't know why it would even come on then.

 

If you're still under warranty I would go ahead and start having them replace parts until the issue is fixed. Better now for free than later for serious coin.

 

That's probably what I'm going to do. It's frustrating because it's failing intermittently and during times when it shouldn't even be used. Why they use this setup and don't just run a lean air to fuel mixture to heat up the engine and exhaust when cold instead. These valves are a decades old design, before electronic fuel injection. There has to be a more modern way of doing the same thing without adding more parts that can fail.

 

If you were to go in and the warranty had expired. Having them repair their OEM special parts with labor runs about $2,000. It's a high profit item and they don't want to change, it's basicly GREED! Sugest you to get them to fix it, and 2 to 3 months before your warranty expires purchase a by pass kit so it won't fail farther down the road. https://www.hewitt-tech.com/store/