spaniel1287

Hey guys, I have tried doing a lot of research about the CEL on my 2000 A4 2.8L throwing a P1411 code. I have been all over my vacuum hoses and made sure that none were cracked and busted. I'm somewhat new to these vehicles and have read numerous places that it could be the combi valves seizing up or have carbon build up in and not working properly. I have also read that it could be the SAI pump itself.

Looking for any advice from anyone who has got this P1411 code before. It is the only code that is being thrown. I did have the car in the shop last week to get the waterpump/belts/pulleys replaced and I had them look at the CEL code. The mechanic told me he found either 2 or 3 hard lines that were snapped and he said he removed and replaced them. He said the CEL then went off. Well after leaving the shop and traveling 75 miles around town, it came back on. I headed over to autozone to get the code read and the P1411 came back up. I have owned the car for about a year now and it has always had the CEL on. I kind of just want some peace of mind and get that dang light off. Thanks for your help and advice.

SmoothJimmo

The Secondary Air Injection (AIR) combination valves are actuated by vacuum triggered by the AIR solenoid. Having the same vintage 2.8 as yours, I can attest to the fragility of the stock vacuum lines after a few years. It is a fairly easy and inexpensive DIY task to replace these lines throughout the engine bay. If you still have any of the original braided hose or the thin, brittle plastic lines, it's time for them to go. Especially the long, thin, brittle line from the blue reservoir below the ABS module and power steering reservoir. Visual inspection is usually an insufficient test. Vacuum leaks can cause all sorts of niggly codes to throw. P1411 is surely one of them.

Fix the easiest, cheapest stuff first. Vacuum lines fall into this category. You'll find vacuum hose and barbed connectors from the local parts store. Make sure to replace one at a time so you remember where they go. You'll have to pull the plastic engine covers and unbolt the unbolt the plastic carrier behind the intake manifold to get to most of them.

You might also consider investing a few bucks in an OBD2 code reader instead of paying Autozone a regular visit. If you have an Android phone, download the free Torque Lite app and get a Bluetooth reader from Amazon like so:
Get the BAFX!! Don't get the slightly cheaper knockoffs. You've been warned!

Good luck!

spaniel1287

It looks like none of the lines are braided except the one going down to mr blue snowman. I guess I can start there to replace all lines.

I did want to see though, I know the Sai pump will only turn on and run for 30 sec or so on cold start up. I have started the car after it sat all night and quickly ran to get under the pump and I even felt it and I'm not sure if it even turned on. I have read maybe the fuse needs to be checked? Any advice from here on what to do?

SmoothJimmo

That last run of braided to the reservoir was a culprit in some strange codes being tossed on my rig some time back. If that few inches of braided line is still there, I suspect it connects to the original thin,brittle plastic line that heads upward, is zipped to the head and then proceeds along the engine valley rearwards. If this thin line isn't there, then it was replaced at some point. I'll retire the vacuum advice at that.

The OBD2 code reader solution I proposed has several advantages. One is that OBD2 codes are often recorded in the system prior to a CEL being thrown. It takes several accumulated errors for a CEL to finally light. The reasoning behind this is manufacturers dont want folks freaking out if the car 'hiccuped' once or twice and then the problem went away. It happens. Since your code will only be thrown at cold start, it may take several mornings of error accumulation before the CEL appears. The FREE Torque Lite app records and can display these pre-CEL error codes. You can also CLEAR the CELs and the pre-CEL codes using these tools. This gives you a fresh error log every morning. You will be able to determine if the problem is solved more readily this way. Clear the CELs and pre-CELs, start the car, then read if the P1411 pre-CEL has returned.

If you plan to keep you A4 for a period of time, you'll want to invest in an ODB2 reader. Get the BAFX if you want an effective, inexpensive solution and have an Android device (btw, I don't in any way represent BAFX, but I have one for each auto in my family fleet...$25 from Amazon).

If you want to dig deeper, consider a VAG-COM system. Then you can play like the VAG technicians and run all the flow and leak tests of the AIR system like a dealership.

spaniel1287

I plan to drive it for a while as it is in near mint condition. I will get all new vacuum hose and start with that. Do you just slip on the new hose or do u put a small clamp/ or zip tie on every vacuum hose? Also, should I get a new black and blue valve thing(sorry don't know the name) or do those never go bad?

If I do replace all hoses and still doesn't fix the CEL problem, where Doni go from there? Actually check the sai pump and what about the fuse? First off which fuse is it that I'm looking for and how can I tell if the fuse is bad?

This morning on cold start engine immediately went to about 1200 rpm then after idle for about 30-45 seconds it dropped down to about 600-800. Is that an indicator that the sai pump was working? Thanks for help.

Also isn't the correct vacuum hose 3.5mm?

SmoothJimmo

How many miles on your 2000? If in such good condition I suspect you live in CA or some other warm weather spot? My 2000 grew up in CA then spent several harsh years in NY suffering the salted roads. It no lives safely in the Seattle area.

The hose will fit snugly onto male fittings and will not needs clamps. You may need to get a few connectors (T and inline) and they can be had from parts stores in kits. I believe 3.5mm is the correct size but take a bit of old hose with you for verification. Buying hose in bulk is cheaper than a kit that contains pre-cut lengths. I would replace that run from the reservoir rearwards as a first stab. Easy to access and a common failure point. I have never replaced the the vacuum check valve (blue-black) since it doesn't get clogged with oily deposits like the PCV check valve (another story). BUT, it is offered aftermarket so it must have a history of failing in some way.

See here for a good supplier of bits including said check valve:

Your Parts Search Returned 3 Part(s)

Cross the AIR pump and fuse concerns bridge when you get there. Hopefully vac line replace will mitigate the symptoms.

The high idle at start for 30 odd seconds is normal even for a rig with a vac leak or AIR issues I suspect. It is controlled by the ECU. My understanding of the entire AIR system is to essentially 'trick' the system into running rich by dumping air into the exhaust stream to fool the Oxygen sensors into reporting a lean condition. Someone please correct me if wrong. There are several of these kinds of afterthought systems on the 2.8. Another is the after-run coolant pump which was probably introduced after hot spots in the engine were causing problems at some point.

SmoothJimmo

Upon review, the AIR system is intended to protect the Cats from extra-rich exhaust during cold startup.

spaniel1287

Thank you for the assistance. It currently has 149k miles on it. Spent its whole life in Iowa, but I don't think my neighbor drove it much in the winters. He took really good care of it and owned it for over 10 years. I dont see any cracking of the vacuum hoses up by the intake manifold. I will replace that line from the vacuum reservoir, however...that line looks not like a vacuum line but like a smaller diameter plastic line. I guess if its coming from the vacuum reservoir it has to be a vacuum line haha.

The other question I had was, I see there are 2 combination/EGR valves on the back of the heads of the engine on the 2000 A4 2.8L. How in the world are you suppose to get to those to see if thats even an issue??? Those things are buried on both sides. I guess I will hope that this vacuum line to the reservoir will be the magic trick.

I will report back in the morning when my wife cold starts the car and I am right next to it to see if it turns on. I have a feeling that it doesn't even run. Thanks for the help and I hope we get this dumb light off!

SmoothJimmo

wow that's clean. I wish mine looked that nice. 3 years unsupervised destruction by the long-distance GF did a number on the finish and the valences. She couldn't resist tall curbs in parking lots. But I digress.
Once any vac leaks are fixed, and presuming that solves the problem, the light won't go out immediately. It will require several "drive cycles" to clear. That's where having your own code clearer comes in handy to expedite the process. Or a trip to autozone to clear. And if it doesn't solve, it will be several cold starts before the light reappears.

spaniel1287

Well the wife had to leave early for work so I am going to try and start the car and quickly go run around front and lay down and feel and listen for that pump. When I took out the airbox yesterday to do some inspecting, the hose going from the SAI pump up to the airbox was filthy inside and all kind of debris in it. Is that normal?