P0492 - Secondary Air Injection System: Bank 2: Insufficient Flow

[Velox]

So I have this code:
P0492 - Secondary Air Injection System: Bank 2: Insufficient Flow



Ross tech wiki says

Possible Causes

Fuse or relay for Secondary Air Injection Pump faulty
Hose(s)/Piping between Secondary Air Injection Pump and Combi (Secondary Air Injection) Valve leaking
Secondary Air Injection Solenoid(s) faulty
Secondary Air Injection Pressure Sensor faulty
Combi Valve(s) faulty
Secondary Air Injection ports in the cylinder head(s) plugged with carbon See Special Notes

Possible Solutions

Check fuse and relay for Secondary Air Injection Pump system.
Check hose(s)/Piping between Secondary Air Injection Pump and Combi Valve
Check Secondary Air Injection Solenoid(s)
Check Secondary Air Injection Pressure Sensor
Check Combi Valve(s)


Since I have the insufficient flow only on bank 2 does this point to are more likely cause from the aforementioned?
Also I have had a run rich condition on the same bank for a few weeks now, am I correct that the insufficient flow could be the cause of this (never had the insufficient flow code before though)

suggestions on what to check first please

[Velox]

Am I correct that both banks have a combi valve each?

[mace115]

Just battled the same code a week ago. Ended up being the hard plastic vacuum line cracked that went into the valve (must've cracked it putting the intake manifold back on). Cut the line and put it all back together and the code hasn't popped up since.

I found it by turning the engine on cold so the SAI system runs and could hear the leak. Looked around and found the crack.

Also to your question, yes I believe both banks have their own combi valve. Right in the back behind the valve cover.

[VinnysS4]

Both banks have their own combi valve. Its usually the hard vacuum line that goes to them that breaks and causes a vacuum leak and inoperable SAI. If youre in need of parts to fix it, I have 2 combi valves, the secondary air pump, and all yhe thE lines and hoses.

Sent from my SM-G550T1 using Audizine mobile app

[Velox]

Thanks guys it was indeed the hard vacuum line that goes into the drivers side combi valve.

There's only about a 3 inches attached of line left attached to the valve and I can't find where it is supposed to go.
I do see a 3 way split in that area like this:



near the oil filter which has 1 line going to the passenger side, 1 line to the front of the engine and 1 piece that looks like it might have snapped but molten closed by rubbing on the head. Which could explain why I dont hear any hissing/leak on startup. Do you guys know if that is the line that's supposed to go to the drivers side combi valve?

[VinnysS4]

The line how back and tees off to both combi valves

Sent from my SM-G550T1 using Audizine mobile app

[Terry.Reese]

Thanks guys it was indeed the hard vacuum line that goes into the drivers side combi valve.

There's only about a 3 inches attached of line left attached to the valve and I can't find where it is supposed to go.
I do see a 3 way split in that area like this:



near the oil filter which has 1 line going to the passenger side, 1 line to the front of the engine and 1 piece that looks like it might have snapped but molten closed by rubbing on the head. Which could explain why I dont hear any hissing/leak on startup. Do you guys know if that is the line that's supposed to go to the drivers side combi valve?

I got a similar sized y extension and redid all of my hoses with non breakable hose, only issue I have now is my SAI is going bad, so I will be deleting it soon.

[OPTIMUSROBPRIME]

2009 A6 3.0T, I have the same issue although I had code P200B(INTAKE MANIFOLD RUNNER CONTROL OVERTRAVEL), first appear which I'm pretty sure is the pvc oil separator as I began hearing a whistling noise from that vicinity. Then code P0492 followed a few days later. I tried swapping relays around and pulling vacuum on on comb valve and the trio of tubing/solenoids for the intake air and actuators. They all are holding vacuum and SAI is working.
I plan on replacing pvc, but contemplating on changing comb valve, sai solenoids, and sai hose. I would hate to just throw parts at it but would hate to have had the opportunity to change them and pass it up. Any suggestions or idea what this could be would help. Thanks

[calebtbay]

I got all the lines to completely replace all the combi valve lines at Autozone for around $30. I replaced the entire line from bank one over to bank two with rubber vacuum line instead of the rigid. From the Y to the front I got a roll of same diameter rigid vacuum line off the shelf. That solenoid on the front is hard to get at with the manifold on so you might want to get inventive.

I would really be interested if it remedies the rich condition.

Nobody mentioned the wires. Im not the only one to have their SAI pump wire jacket turn to dust. The million wires around them still look new but those two wires were absolutely toast on mine. Might want to check for shorts at the pump connector. Easy to check.

[OPTIMUSROBPRIME]

I am currently replaced the pcv and thermostat, waiting on coolant hose (horizontal in front of engine )to come this saturday as I broke it. I have vcds coming today, but I think I will throw everything back together. Then check to see if the issue has been resolved or what to check next, all my hoses hold vacuum and trio valves, even the combination valves hold vacuum. I'll definitely post back soon I get everything together.

[OPTIMUSROBPRIME]

Changed PCV and air inj. solenoid bank 2, I still got a whistling noise and p200b. Here is what it sounds like https://youtu.be/Y_XnOL8N-AA?si=7LFYWDEv4xGQP3U2