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P0410 and P1411 - Running Out of Ideas

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Hello all;

I'm hoping you can tell me what to do next.

For the past several months, I have been getting two codes and no other ones. The two are P0140 and P1411. I have replaced the air pump, the MAF sensor, all the check valves, and any broken vacuum lines. With all new parts and the secondary ari system holding vaccumm, the CEL and the two codes keep returning. Other than the two codes, the car runs great and oner would know there is a problem.

So I have two questions foir the forum?

The 01S has 90K miles so next week I will replace all four O2 sensors. If that and the full repair of the secondary air system doesn't resolve the CEL light / two codes problem, what you suggest I check next? Second, does anyone know how I might ask Porsche North America. The local dealer will only escalate the question if I spend another couple of hundred bicks for further diagnosis before they will pass the question on.



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I just fixed the P0410 code. I replaced the air change over valve and the electric change over valve.

Both are under the intake manifold.

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You would have different codes if the O2 sensors were at fault. Don't waste your money on O2 sensors .

P0410 Secondary Air Injection System, Bank 1 – Below Limit

P1411 Secondary Air Injection System, Bank 2 – Below Limit

Possible cause:

- Secondary air injection pump is not triggered

- Secondary air injection pump does not function

- Air supply lines restricted

- Electric change-over valve does not function

- Air change-over valve does not function

- Vacuum system leaking

So the first question is does the air pump run for a couple of minutes at cold startup?

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Thanks. I;ve changed all the parts in the secondary air system and the MAF, I've also verified that the system is holding vacuum. 410 and 1411 still appear. That's why I'm out of ideas as to what to do next.

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So, you reset the codes and they come back?

Then there still gas to be a leak in the system - either lines or a fitting.


Here is the diagnosis procedure...


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Yes, I've had the codes reset multiple times. About 50 milles after each reset, the codes reappear on the first cold start within couple of minutes driving. The shops have smoke tested the vaccuum several times and they found no leaks.

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Just out of curiosity what led you to believe you had to replace the entire secondary air system? Was the air pump defective? I only ask because I had a similar problem last year and was told I needed to replace the entire secondary air system after two smoke tests revealed nothing. I found a mechanic who took off the intake manifold and found a small hose in the system had pulled off the valve. Once reconnected both codes went away and never returned. I agree with Porsche Nut you've still got a leak in that system somewhere. Have you checked the small bellows shaped rubber connector at the vacuum tank? Unless you are certain the O2 sensors are defective you are wasting your money replacing them.

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The car has been to the shop multiple times. First, they checked for vacuum leaks and found some, These were fixed. Codes reappeared. Then the various secondary air valves were replaced. I took the view that labor costs were the biggest part of the bill so replacing parts when things were easily accessible was the less risky approach. The codes reappeared. Then the air pump was replaced. The code reappeared agan. Then the MAF was replaced. Still the codes reappeared. It always the same story. Clear the codes; drive at leaset 50 miles; the light and the codes come back on at a subsequent cold start. Now with nothing left to fix in the secondary air system, it's on to the O2 sensors. They're paid for and in hand so it's cheap to actually put them in given the car's high mileage. So I've done everything I can think of. The two independent shops - unless they are both incompetent - have gone through all the diagnostics and have nothing else to recommend. The local dealer wants to start back at square one and charge big bucks before they will either escalate my question to Porsche or recommend what else to do. A smog test two months ago showed the cats are working great and the car is running very clean. So if all else fails. I might just set the car to ROW and have the secondary air system ignored by the diagnostics because I just don't know what to do next.

Edited by thom4782

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Go ahead and try one O2 sensor. That is the only input the car's computer uses when it decides whether to throw that code. Here's a quote from the Porsche training document...

The monitor for air injection monitors the oxygen sensors

in order to detect if air is actually being injected into the

exhaust. It looks for the oxygen sensors to drive the

voltage low (low voltage high oxygen content in exhaust),

since normally the sensor voltage would be high due to

the rich start up mixture. The only way that the sensor

voltage will fall close to ground is if air is actually being

injected into the exhaust.

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I've been experiencing these codes for a while too. I have new pre-CAT O2 sensors (within the last year anyway) and I can hear the pump coming on, so that doesn't appear to be the problem, but it occurred to me as I read your post that your codes appear to take much longer to come back than mine. Since everything else seems to check out, I wonder if you're experiencing intermittent pump relay problems? On my 951, when my headlight relay started to go out, it would work sometimes, and not others. It went on for over a year this way before it finally created a real problem for me and I tracked down the source of it. An interimittently-functioning relay would make reproducing the problem on demand very difficult.

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Hi i had simulair problems and I replaced the AOS (altough it was not smoking) but this solved my issue!

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