P0492 Check Engine
Thread Starter
Melting Slicks
Joined: Apr 2023
Posts: 2,734
Likes: 1,610
From: Poplar Bluff MO
P0492 Check Engine
I have a 2004 and got a check engine light, checking the code it's P0492 Secondary Air Injection Bank 2.
I found a fix online at Motortrend and did the flush from the connector on the driver side inner fender and cleared the code. Drove a few hundred miles and the check engine light came back on. Repeated the same flush and after a hundred or so miles the check engine light came back on.
I decide to flush only the bank 2 check valve (located behind the intake manifold or so they say, can't see it) by plugging off the bank 1 check valve. Long story short flushed twice and still got the check engine light.
Now I really didn't want to take the intake manifold off to replace the check valve... well one day I was feeling a bit spirited and did a few 1-3 near redline launches going to town and while in town (1-2) on the way home the check engine light went off. Now the moral of this story is sometimes it pays to blow the carbon out.
It's been a few months and the check engine light has never came on again.
JT
I found a fix online at Motortrend and did the flush from the connector on the driver side inner fender and cleared the code. Drove a few hundred miles and the check engine light came back on. Repeated the same flush and after a hundred or so miles the check engine light came back on.
I decide to flush only the bank 2 check valve (located behind the intake manifold or so they say, can't see it) by plugging off the bank 1 check valve. Long story short flushed twice and still got the check engine light.
Now I really didn't want to take the intake manifold off to replace the check valve... well one day I was feeling a bit spirited and did a few 1-3 near redline launches going to town and while in town (1-2) on the way home the check engine light went off. Now the moral of this story is sometimes it pays to blow the carbon out.
It's been a few months and the check engine light has never came on again.
JT
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Ive taken those check valves apart. They use a thick rubber disk to control air flow. The rubber disk bends to allow A.I.R. air flow to happen at a specific cfm. When the disk gets hard, dirty and stiff, it fails to flow the proper air cfm and it trips a DTC due to the O2 sensors not seeing the EXPECTED fresh air flow into the exhaust stream during A.I.R. scheduled operation.
As ztheusa stated, The DTC will be back and you need to deal with that check valve. That flush is just a band aid at best. .
BC
As ztheusa stated, The DTC will be back and you need to deal with that check valve. That flush is just a band aid at best. .
BC
Burning Brakes
Joined: Apr 2017
Posts: 968
Likes: 322
Its broke will need to be changed. While the manifold is off great time to replace the knock sensors, and oil pressure sensor. PCV valve and just clean up top of engine cheap and good for another 100000 miles. But that's me.
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Thread Starter
Melting Slicks
Joined: Apr 2023
Posts: 2,734
Likes: 1,610
From: Poplar Bluff MO
JT