Hello everyone, 04 A4 B6

I am just about to go insane with this issue, cant pass my emission test because of this. So far I have replaced all the vacuum lines to ensure there is no leaks. I have changed the n80 valve ( I put the b7 one instead of the b6 one )
Everything I try leads me back to this issue. Latest try I cleared the codes waited for the systems to go ready, for about 5 days it showed no errors, but just today the check engine light isnt on yet but it showed the code.

The only thing I havent done is change the relay in the ecu box regarding the SAI.
What am I missing here?

Also which way does the one way valve and the n80 valve flow?
Any help would be great

 

I'm not 100% certain here, but I think you're looking for the n112 solenoid. Maybe another member can either confirm or deny this.

 

I definitely haven't checked that or the relay j299. Water did get into my ecu box a while ago, also when I cold start I do hear the sai for slightly over a minute then then rpms idle down. So would that eliminate the relay?

 

If it's starting when you first turn on your car in the morning then I'd say the relay is good. You should certainly hear it when it first turns on as you'll notice the noise coming from the engine bay changes after about a minute and a half when the cats are heated up.

You could have a kombi valve that's on its way out as well. I would pull up the codes again and see if it's from bank 1 or bank 2. Once you know that you can narrow your search down to a particular side.

 

This worked for my 1.8. check the discharge line from the air pump up to the metal pipe for leaks. that metal pipe goes to the combi valve and that pipe has rubber elbows in it that rot. At cold start, remove the vac line from the combi valve nipple and see if vacuum is present in the line, by letting it suck your thumb. If vac is there, then your combi may be bad. remove the combi and suck on the nipple to see if it actuates.

I guess you have two of everything I just mentioned.

 

Just to give an update, ended up paying for vagcom, here's the code


VCDS-Lite Version: Release 1.2

Control Module Part Number:

Component and/or Version: 1.8L R4/5VT G 0003



1 Fault Found:

16795 - Secondary Air Injection System: Incorrect Flow Detected

P0411 - 002 - Lower Limit Exceeded

-------------------------------------------------------------------------

So I ran output test

my n80 was clicking, n112 was clicking then i heard this plunger sucking sound coming from the n112 and nothing else.

on the j299 relay test i only hear clicking (dont hear the pump coming on, from what i read i should hear the air pump cycling?)

So i decided to pull out the ecu box next to the battery and the contacts j299 relay was green and salty looking and looks like water got into the ecu box before.
Would the relay click and not cycle the air pump if it was on its way out?

When I do cold start my rpm goes to 1300 rpm then drops a minute or so after. the car engine sounds louder for sure where could i listen to to hear if the sai is turning on?

I will remove the lines from the combi valve to see if it can replicate the conditions.

 

id just slip the dude 100 bucks and ask for it to pass... works 100%, 80% of the time...

just grow a mustache they wont be able to say no.

besides secondary airpump is a joke it literaly works for like 2 sec when you start the car....thats it.

 

Unfortunately they changed the system here this year and you can only pass once it's plugged into your obd slot so I can't even take that option lol for cars newer then 2001

 

Does the relay trigger the air pump? Should it cycle when I output test the relay? So is my relay gone?

 

Ended up buying a relay and it worked pump was cycling in the out put test, just waiting for the oxygen sensor heating system to go ready then I can finally pass it