USMC1986

I'm very new here and not to familiar with Audi vehicles so excuse any lack of knowledge. I have a 04 Audi A6 S-line with a 2.7 NO MODS, and after swapping the secondary coolant pump I've been left with an awful miss at idle, slow speed, and high speeds. I've pulled the codes using an OBD-2 computer(I know i should use VAG-COM but my interface cable has mysteriously disappeared). The codes are as follows:

P0491: Secondary Air Injection System Insufficient Flow Bank 1
P0102: Mass Air Flow (MAF) Circuit Low Input
P0237: Turbocharger Boost Sensor A Circuit Low
P0106: Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem
P0343:Camshaft Position Sensor A Circuit High Input (Bank 1)
P0348:Camshaft Position Sensor A Circuit High Input (Bank 2)
P0356:Ignition Coil F Primary/Secondary Circuit Malfunction
P0175: System too rich (Bank 2)
P0172: System too rich (Bank 1)

I should mention P0491, P0175, p0172 were present before I swapped the secondary coolant pump was replaced. The car doesn't start on the first crank which I attributed to P0343 and P0348.

Can anyone give me an idea of where to start with this vehicle?

georgeb944

Category:Fault Codes - Ross-Tech Wiki

redbullgotwings

My first thing would be to fix the MAF problem. A bad MAF can lead to a number of other issues.

so youres saying all these popped up after you replaced the secondary coolant pump?
Did you unplug things to replace that? I dont know the process. If you did unplug stuff i would save that read and clear it to see if maybe it just didnt like be unplugged.

But i would replace the MAF then clear and test drive and scan again.

USMC1986

The MAF has been replaced and I'm still having the same problem. There were all kinds of things that needed to be unplugged in order to reach the secondary coolant pump. I followed these instructions:
AudiWorld Tech Articles

Should I have reset the throttle body after I took the intake manifold off? When I clear the codes it runs normally for about 5 minutes and then the EPC light comes on and the car goes into "limp mode", and I lose all throttle response and the car stalls out. It idles fine, but when you put it gear and give it gas it then stalls out. Any more suggetions?

redbullgotwings

do you have vag? Im no expert but it sounds like youre fully in limp mode now. It sounds like you need do a TB alignment. Im no expert tho.

Do you still have all the same codes? MAF and everything?

USMC1986

I do have VCDS, but my interface cable has fell into a wormhole or something. I can't find it anywhere. It is still throwing the MAF code and everything else that I had listed. I'm going to try to do the TB alignment tomorrow using a method that doesn't require a computer. Hoping it works, but based on my experience with this car, a good amount of cash is what it is going to need

redbullgotwings

So ignition coil F, I ignored that at first cuz I didn't recognize it... I'm guessing that's cylinder 6. I've never seen that code before I've only seen it say cylinder 6 misfire.

Clear the DTCs, then swap coil 6 with five. Coil six is right side front.
1 4
2 5
3 6

If coil F becomes coil E then you have found your problem

If that's not the problem, I think you either broke a wire or forgot to plug something back in during your secondary coolant pump install.

USMC1986

I will try that. Also, noticed yesterday that the fuel pump isn't building up pressure in the lines when you turn the key on. Only when you try to crank the motor will it begin to spit fuel into the lines. Luckily, I still have a warranty on it so I'm gonna swap it out as well just in case.

I've triple checked all connections and electrical relays to see if I might have missed something, but it appears everything is hooked up well and where it should be. I suppose there is a chance there is a broken wire, but I have yet to locate it. Resetting the TB did nothing, as I hoped that it would.

SloopJohnB@mac.com

I think it's:

Windshield
^
1 6
2 5
3 4
^

clancy

HUH? I see 3 different answers in your post. I vote for the larger more detailed diagram.