View Full Version : Audi A4 2.8 quattro error code P1122

02-10-2013, 04:18 PM
Hello all,

I recently purchased an Audi A4 2.8 V6 quattro from the year 2000 and I'm having some issues that maybe someone could help me out with.

The car has the Check engine light on and the code that is read on a computer is P1122, which I found out online it's one of the O2 sensors. My problem is that my mechanic checked them and says they're good?!? How can that be??
Should I go ahead and change them? Also, my oil temperature gauge always reads zero, never moves at all, could this be related?
What I've read is that if the O2 sensors are faulty, the consumptions go to crazy levels, and that's exactly what I have, it drinks gas like there's no tomorrow.

The previous owner had a direct air intake which I took out. Had to buy the top portion of the air box as it was missing, and I'm still waiting to get the Intake elbow adapter tube that connects to the air box coming from the air pump. That same pump is currently disconnected. Could any of this be related with a P1122 code? I don't know what exactly to do as if I take it to Audi they really don't care, they'll replace all O2 sensors, charge me an arm and a leg and maybe that's not even the issue.

Any help would be tremendously appreciated, as the car is very low mileage, it's now at 157k and in very good condition, just sucks to be having all this issues and not knowing how to solve them.

02-10-2013, 04:42 PM
Your mechanic may be wrong. I think P1122 is for driver's side rear O2.

As far as the hole in your airbox - plug it or even tape it shut with gaffers tape for now. It may be throwing your ECU off, especially if you haven't unhooked your battery since removing the old intake, so also do that and a throttle body alignment.

With your oil temp issue give this thread (http://forums.audiworld.com/showthread.php?t=2763857) a look.

02-10-2013, 04:42 PM
P1122 = O2 Sensor Heater Circuit. Bank2-Sensor2 Open

As far as o2 sensor codes go, that one is pretty cut and dry. It doesn't have to do with the "sensor" part of it, just the built-in heater. 95% chance a new o2 sensor will prevent that code from coming back. 5% chance there is a wiring fault. You don't have to guess, though. You can unplug the sensor and check the resistance across the heater element for that sensor. You can compare it to the resistance from the other bank's o2 sensor. No guesswork. No buying parts on a whim.

That said, a heater code doesn't really explain a fuel mileage complaint, however you do want to fix all known faults before you go after MPG issues. Good Luck.

02-10-2013, 04:43 PM
17530 P1122 O2 Sensor Heater Circ.,Bank2-Sensor2 Open

replacing that particular sensor would be a good place to start. no need to replace all 4.

02-10-2013, 08:46 PM
Thank you so much to you all! I'm gonna do that, one thing at a time. Just feel overwhelmed right now, and I love this car so much that I guess it affects me more than normally to see all this little issues :(
I'll keep everyone posted as to what is going to happen as it may be useful for other Audi owners with similar issues.

02-11-2013, 08:32 PM
what kind of milage are you seeing? quattro? TIP or 5 spd?


02-11-2013, 08:36 PM
It's a quattro, 5 speed manual. On the highway computer reads between 9 and 11L doing 100km/h.
Actually, it's been better since I took out the direct air intake with this stupid performance filter jammed in there.

02-14-2013, 02:33 PM
Hello all again,

As someone said here before, changing the O2 would be a good start...
Well I changed it, engine light went off, but after half hour went on again. This time is giving me a P1296, which by what I read is either the coolant sensor or the thermostat.
The computer the mechanic is using only gives us one error at a time, so I may have another 10 errors in line...FML!
Next should be the oil sensor as my oil temperature gauge is dead, doesn't even move...I hear the coolant sensor is pretty cheap, so I believe it's worth a shot replacing it. But how many sensors are there on a 2.8 V6? Does anyone know is there's more than one and where are is it located?

Again thanks!

03-08-2013, 09:01 PM
I changed the coolant sensor and reset the computer, all is good now. No check engine light anymore :) The car is pristine.
Thanks for the input, always very helpful.
I've been thinking about lowering it as I find it unusually high. Does anyone know if the struts have to be changed, ot the springs alone would do it? I don't want to slam t, just lower it 1 1/2 inches to 2 inches max.