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Discussion Starter · #1 ·
Argh. Wife's darling Equinox is giving us headaches again. Thankfully this came up a few weeks after it got e-checked, so we have some time to fix it. Has come up twice in the last couple weeks. A Youtube video indicated one possible problem is carbon build up in the air injection ports, mentioning that the exhaust manifold and the cat have to come off to fix it (yuck).

So is there a usual culprit for it? I did slow down the oil consumption substantially with a treatment of BG EPR about 2000 miles ago. I wonder if the oil burning fouled up the exhaust manifold and clogged up the ports.
 

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Discussion Starter · #2 ·
Ooh... I just learned about the 2.4's cracking exhaust manifolds. If it is cracked at 80,000 miles (I haven't looked yet), I would think that could be throwing off the pressure sensors and could trigger the code, is that possible? I guess if the manifold has to be replaced, that might take care of the injection ports.
 

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2010 chevy equinox lt 2.4, 135k miles. Mocha steel metallic mobile 1 full syn extended performance
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Yea it could since the upstream 02 sensor detects 02 levels in the exhaust i'd also say u may want to check out the air injection system in the process because. It's detecting low oxygen levels but the 02 sensor detects 02 levels both on the inside and outside of the exhaust if there is an exhaust leak near that sensor it may trigger some funky codes because there's no code for low oxygen OUTSIDE the pipes the car can only guess based on the voltage the 02 sensor puts out.. The higher the difference in o2 between inside and outside the exhaust causes a higher voltage... It wants to read a low voltage when that pump kicks on but for some reason that's not happening possibly pump not working/ exhaust leak. Check out the manifold and remove the 02 sensor make sure it's good the crack usually is right up near the o2 sensor and u usually can hear or smell it. If that is your only code I would say it is the air injection system... If all is working good make sure u also change the air filter because thay intake is for both the engine and air injection.... May be clogged. U should either reset the computer or it needs to complete several tedious drive cycles to actually clear on its own.
 

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'16 Equinox LTZ AWD 3.6
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Cracked manifold should not affect it. Drove my 2.4 Malibu to 190k miles with it cracked. I would suspect it's pressure sensor myself.

P0411 CHEVROLET Meaning
The Secondary Air Injection (AIR) System aids in the reduction of hydrocarbon exhaust emissions during a cold start-up. This occurs when the start-up engine coolant temperature (ECT) is between 5-50°C (41-122°F), and the intake air temperature (IAT) is between 5-60°C (41-140°F). The AIR pump operates 5-60 seconds after start-up.
The powertrain control module (PCM) activates the AIR system by simultaneously supplying grounds to the AIR pump and the AIR valve relays. This action closes the relays' internal contacts. The AIR pump and the AIR control solenoid valve/pressure sensor assembly are in turn energized, the pump runs and the control/shut-off valve opens.
The AIR pump sends pressurized fresh air into the pipes/hoses through the open control/shut-off valve, and into the exhaust manifold. The extra air accelerates the catalyst operation, helping it to reach operating temperature faster. The AIR pump remains ON for a short period of time after the control/shut-off valve is commanded OFF. When the AIR pump is commanded OFF it will not run or be activated until the next vehicle start. When the AIR system is inactive, the closed AIR control/shut-off valve prevents air/exhaust flow in either direction.
The AIR system pressure sensor is used to monitor pressure at the AIR control solenoid valve/pressure sensor assembly inlet during the commanded ON/OFF states.
 
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Discussion Starter · #5 ·
So we have less than a year to fix her darling Veganox for this P0411 that's been on since I first posted, it's due for e-check again come 2023. All I've been able to determine is that the pump runs, the hoses aren't clogged, and the air filter isn't clogged. Have a bad feeling it's either the check valves or the carbon buildup. Ordered a new check valve, but watching a Youtube I realized there are two of them (whoops). Also found that while I could probably take the exhaust manifold off myself, the TSB mentions replacing all the studs, and it doesn't look easy to get to back there. Also I don't have the fancy scan tool to control the check valves or the pump. Anyone have any idea what it would cost to clear the ports?
 

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'16 Equinox LTZ AWD 3.6
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I would replace the sensor first before doing anything else.
Sensors are the most common thing to fail. GM sensor only.
 

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Discussion Starter · #9 ·
I picked up a bidirectional scan tool, and I've been able to confirm that both sensors read atmospheric pressure with the pump off and the engine off, and if I command the air pump on and the valves open, they both read slightly higher than the threshold that triggers the P0411 code. Both check valves are clicking as they should when they are commanded open. So, it's looking like the TSB about clearing the carbon from the injection ports is what it will need. It doesn't sound too awful taking the exhaust manifold off, but has anyone attempted to clear the ports? It stinks that the TSB mentions there is no permanent fix. Like every car requires routinely removing the intake manifold to clear the PCV hole or removing the exhaust manifold to clear the air injection ports...
 

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Discussion Starter · #10 ·
Any have any ideas on cleaning the carbon from the ports? Thinking I'm going to tackle this soon before it gets too cold. Found some Youtubes on removing the exhaust manifold, so I'm thinking it's something I can do.
 

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Discussion Starter · #11 ·
Well, rats. Had to admit defeat and took it to a shop. It's a more difficult job than I thought, and the shop admits it's a difficult job. They concur it was clogged ports. They called back with an update; not only are they clogged, but they found the exhaust manifold is cracked! This car is such a piece of junk. I had to drive my 1977 MG Midget to work today since the wife has my Pilot, and realized that between my former 2010 Traverse, her 2013 Equinox, and the MG, the MG has been pretty darn reliable. That's right GM, the 45 year old car that is notorious for rust, electrical problems, vapor locking, dis-connecting rods, and a transmission that can engage reverse and first gear simultaneously has been more reliable than either of those.
 

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Hi, I just finished this job on my partners car. And I ran into the same thing with the cracked manifold. Did you take it to a GM garage or somewhere else? AWD or FWD? I’m curious to know what your bill was for all of the work including the manifold replacement.
 

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Discussion Starter · #13 ·
Hi, I just finished this job on my partners car. And I ran into the same thing with the cracked manifold. Did you take it to a GM garage or somewhere else? AWD or FWD? I’m curious to know what your bill was for all of the work including the manifold replacement.
Hi, I took it to an indy shop. I don't have good experiences with GM service techs, but the indy shop confirmed what I had found and got it fixed. It ended up being $1200 to clean out the ports and replace the exhaust manifold. They also changed the oil because it was nearly due and they said they had to use a lot of solvent to clean the ports so they wanted to make sure the oil wasn't contaminated. It's an AWD. Light's still off, and I got it to pass the e-check this weekend.
 
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