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Had a check engine light for secondary airpump kick on. Took to dealership they said the secondary airpump was bad. It got replaced, engine light was off for about 400 miles then popped back on. Brought it back in and they said a hose going to it was clogged. Had all hoses replaced and engine reset. Light was off for about 120 miles. Now lights back on. Brought it back said everything is fine did a reset and 20 miles later check engine is back on. Now I need an inspection but here in NY it won't pass since I have a check engine light on. What to do, how to fix. I need a solution. Any help greatly appreciated.
I saw this some time ago somewhere on the net so acknowledgement to the unknown author.
Really good mechanics will tell you the fault codes reported by the OBD are simply an indication of a problem in a particular system and don’t necessarily identify the root cause.
What’s missing from the reported fault code is WHY! Does the code mean the component is faulty or does it suggest the component can’t operate within its normal range because something else is broken? Why is the engine management system reporting that the mass air flow sensor is out of range/performance?
This could be caused by a defective mass air flow sensor, but it could also be a vacuum leak, a split intake air boot or PCV hose, a defective intake manifold gasket, wiring or connector problems etc.
Seems like the dealership is ignoring the WHY and just running through a replacement program $ by $. As you don't seem to have the diagnostic gear I could only suggest that you find an ethical mechanic.
I agree. It could be something like a crispy vacuum line to an SAI valve and the shop is lazy and soaking you.
My 957 does not have SAI but I have dealt with it on my Audi S8 and the vacuum lines to the air->exhaust valves get cooked and leak, and there can be issues with the lines at the solenoid vacuum valves that control the valves.
Guessing #4 is the control valve and #14 is the air->exhaust valve: https://www.sunsetporscheparts.com/v...jection-system
The right side pump on my 2006 S died last week. I got a P0491 and the CEL. I found the 40A fuse for it blown. Found about 2/3 of the vanes on the impeller of the pump broken and laying inside the pump, jamming it and preventing it from turning. Some of those pieces inevitably end up in the check valve, which is downstream of the pump. Apparently, if you don't pull the check valve and clean those out, the check valve may be stuck open. From what I've read, the DME monitors proper pump operation by the reaction of the O2 sensor when the pump is on. If the check valve is stuck open, I think that could cause problems, even after the pump is replaced. I couldn't find a good "description and operation" of the system in Alldata. Maybe somebody out the has one and will post it here.
Agreed. Pump fails sends foam and chunks of the impeller into the hose and intro the egr valves. Pull off the valves and have them cleaned. The valves sit at the other end of the the hose.
I took the right side check valve off today, and sure enough, the hose was loaded with impeller bits and sticky foam residue. It was mostly stuck at the sharp bends. I got it all out and blew through the hose with compressed air. It's interesting to note that the check valve is just that - a check valve. There's no vacuum hose controlling it. I assume that the pressure the pump puts out is enough to overcome the spring in the valve allowing it to open and allowing the pump output to enter the exhaust system. It's not an EGR valve. It's black and carboned up looking on the exhaust side and very clean on the air pump side. I put it back together and am now waiting on the used OEM pump I bought on eBay.
Most of it has already been covered, but I will input my experience for reference..
I initially had a CEL light for the SAI system and found one of the fuses blown. This was due, as mentioned above, to a failed pump. the pump failed due to the foam filter degrading and getting ingested by the pump breaking the blades off the impeller. I replaced the pump and the fuse, and cleared the code. I then monitored the status of the readiness code for the SAI, which eventually failed again, though it took quite a while. upon investigating I found that there were vane pieces stuck in the valve and additional pieces in the hose. with the valve stuck open the exhaust pressure blew vanes from the original pump back upstream into the replacement pump jamming the impeller of the new pump and burning out the motor.
I replaced the pump a second time, and this time cleaned the valve and hose out. the valve should not allow exhaust pressure to blow back into the hose.
I also opened the remaining good pump from the other side and investigated the condition of the foam filter. this filter had also started to fail and liberate bits of foam into the pump, but not enough to damage the impeller yet. I removed the remains of the filter, so the pump will draw unfiltered air, but since the pump only runs periodically under certain cold start conditions I feel the risk of ingesting anything large enough to damage the pump is extremely rare, so am satisfied to run it unfiltered for now.
The reference, the replacement pumps I bought were aftermarket pumps and aside from contaminating the first replacement due to parts left in the system from the failed OEM pump I have had no issues with them since.
Moral of the story, is if you have a failed impeller, you need to remove the hose and valve and clean them of all debris from the original failure, or the fix is likely to be unsuccessful.
I too bought some pumps that were for a 90’s Camaro or something like that. Can’t remember, though I posted about it on Rennlist years ago. Pumps were identical. Had to swap out the housing or electrical connector to make it fit. Was simple and a fraction of the price of OEM pumps. A quick scan of the normal parts sources (FCP, etc) shows aftermarket pumps are now available.
As for the OP that had the initial problem. The dealer should have caught the clogged hose, the clogged valve, etc. The impeller and foam that fails has to go somewhere….
Perfect timing!
I just started getting code P0492 a few weeks ago.
Haven't taken a look yet but I'm betting I'll observe the same as everyone else.
Just ordered the Amazon type part from eBay for $60 with a 20% off coupon.
To follow up, my CEL came back. Happily I found the maxi fuse to be blown.
Replaced the fuse and while I was there I connected a small shop vac to the hose. Nothing got sucked out so I'm optimistic that this will be the end of the fun.
I'll just add that you really can't eyeball the fuse to see if it's blown. I used a meter.
The orange 40's are the guys and the upper one in the pic is for the left side (bank 2).
An update on mine - I bought a used OEM pump on eBay. I opened it up and found that the original foam was still in there and intact, so I took it out. The 40A fuse for that pump had blown too, probably because all the broken vanes jammed the impeller and stalled the motor. I installed the eBay pump and a new fuse. It's been a few weeks and the CEL has not come back on, so I feel confident that it's fixed.
05-30-2024, 11:32 PM
Secondary air pump
