6 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHSAI issues, codes P0491, P0492
Leading reported evidence
Check satus of the sai pump
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Leading evidence: 'Check satus of the sai pump' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check satus of the sai pump' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
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Suggestion · Original poster
I disconnected the hose from the pump, to check if it blows enough air.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion · Original poster
In two weeks I will have the transmission and torque converter out for a rebuild and modifaction so I will have time and space enough to inspect the whole SAI system.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
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Suggestion
To me it was easier to replace all the hoses/joints etc.
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Suggestion · Original poster
In two weeks I will have the transmission and torque converter out for a rebuild and modifaction so I will have time and space enough to inspect the whole SAI system.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
6 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
When the sound disappears Idle rpm falls back to normal.
Today I checked again my car with durametric and saw the following codes
P0491: Secondary Air Injection System, Bank 1: Insufficient Flow
P0492: Secondary Air Injection System, Bank 2: Insufficient Flow
I checked the satus of the SAI pump. When I toggle it I hear it running.
I disconnected the hose from the pump, to check if it blows enough air. To me it seems the flow rate is good. I know I need to look further down the lines and valves of the SAI sytem to see if there is something blocked. For this I came accross other threads on the forum that go into detail where to look when these codes appear.
However I noticed the following
1. recently, when coming to a stop, i.e. when leaving the highway. I hear a whirring sound kicking in for some seconds. It sounds to me as it is the SAI pump. But I am not 100% sure. At the same time with the whirring sound I see the RPM at idle going 100rpm or so higher. When the sound disappears Idle rpm falls back to normal. Is this possible? I thought that the SAI only kicks in at cold start to speed up heating of the cats.
2. Further I notice at cold start, car sits overnight, that the exhaust smokes for 3-10 seconds (warm or cold ambient temperature, makes no different, it smokes). To me it is not oil burning. Had that before and know how oil fumes look and smell. Water I doubt it is, as in warm ambient temperature it also smokes. It is whitisch but doesn't smell like burnt oil. It smells more as fuel, could that be white too? Could this be related to the SAI malfunction? As if at cold start the ECU injects more fuel to heat up cats but the SAI does not provide the necessary extra air to burn te rich mixture? Unburnt fuel exits the exhaust as white smoke?
Engine is further running Idle very stable at all times, cold or warm start.
Besides that I also had the P0420, P0430 codes pending
They read as: Cat conversion Efficiency bank 1 & 2
No CEL light in the dash; those two codes are coming most probably from the 200cell cats of the x-pipe. So unrelated to the above issues, I suppose?
I would check out Part #'s 9 and 11 first here:
http://www.autoatlanta.com/porsche-p...section=108-05
The check valve is prone to getting gummed up.
Also, there are two changeover valves Part # 18. Known to go bad.
It is not unusual for the SAI pump to kick in after a highway run. Just seems to be one of the quarks of the system.
The smoking exhaust is not all that uncommon either. If you are not losing oil or coolant, it most likely is a result of the error codes and SAI system. How many miles on your AOS?
This thread should help
https://rennlist.com/forums/996-foru...not-ready.html
The SAI pump kicks in after highway run is normal and is by design. The DME does that if it didn't have a chance to check the SAI operation during cold start (e.g., if you drive the car off immediately without much idling). The drop in the rpm was because of current draw (a lot) from the SAI pump, which loads up the alternator, then in turn the engine raises its rpm to compensate.
I had the same codes. I replaced basically everything shown in Ahsai's picture, and haven't had problems since. To me it was easier to replace all the hoses/joints etc. than figuring out which one leaked. Plus if one was cracked, the others probably wouldn't be far behind.
Thx Ahsai and Joe ... Your input has been as always very appreciated!
Will have a look at those valves pointed out.
The links posted contain a whole lot of detailed info for analysis. Especially the read-out of the pre-cat O2 sensors at cold start. Will try to have a graph with durametric.
In two weeks I will have the transmission and torque converter out for a rebuild and modifaction so I will have time and space enough to inspect the whole SAI system.
