Secondary Air
Injection Incorrect
Upstream Flow Detected

What does all this mean? as far as repair? and cost?

 

Well....... what car is it?? need more details.

 

^This. With that little amount of information, could be a bad MAF sensor, vac leak, busted secondary air injection pump, etc. And you could spend days and many hundreds of dollars replacing **** trying to fix it.

 

sorry guys. 1st time user of any type of forum.
it is a 2000 A4 Turbo with 150,000 miles.
i did search this websiet and found an entry from a couple of years ago that said "p0411 solved!" and they basically said it was a small hose coming out of the drivers side of the combi valve that needed to be replaced.
which was great to find a fix, but i have no idea what a combi valve looks like or where it is at on the car, if some one could post of picture for me that would be awesome!

 

the small hose they're talking about is a vac line. Basically, your car stores the vacuum created by the motor and uses it for different ****. The OEM vac lines are rubber covered with braided cloth, and over time they get brittle and break, causing that stored vacuum to leak out.

The combi valve is on the back of the cylinder head, located just to the left (if you're standing in front of the car) of the coolant temp sensor. I've circled it in red in this pic:



There will be vacuum lines coming off of this, check them out and see what they look like. You can pull off a chunk of vac line, take it to autozone, and they'll set you up with the right sized line.

 

i threw that code when i first bought my car, turned out to be maf, which was then replaced by a catayltic thresh hold code, they never end! but the new maf fixed the po411

 

PO730 A41.8 Automatic

 

po170

 

Just diagnosed this code on my car. It turned out to be a broken plastic air pump tube. This is one connects the air pump in the front passenger corner to the metal tube that comes up over the turbo and valve cover leading to the combi valve. I have already had to replace the relay which was stuck in the closed position which drained my battery. Here would be the escalating costs of replacing fixing the SAI system.

1. Vacuum tubing or gaskets 5.00
2. Check valve 5-10.00
3. 373 Relay 5-10.00
4. Secondary air pump tube 12-60.00
5. Combi valve 60-90.00
6. Secondary air pump 90-270.00
7. New head 200-500.00 (assuming carbon buildup has completely clogged SAI ports)

These are all the things I can think of anybody else know a component of the system that may lead to a code?