Hope you guys can help-

2000 A4 B5 1.8T ATW

Sequence of events:

-Fuel Too Lean code for past 2 weeks (drove fine)
-Cleared code, drove car
-Car immediately drove terrible, CEL started flashing (Misfire)
-Random misfires, all cylinders
-Found ripped vacuum hose under hood, replaced with cheap hose from home improve store until OEM can arrive (it looked comparable)
-Cleared codes
-Car feels like it just isn't breathing
-Pedal to the floor car barely picks up
-CEL: Random Misfires, Cylinder 3 & 4

I'm going to get new coil packs tomorrow, but does this make sense to anyone?

 

Don't start throwing money at it. If you don't guess correctly you'll have wasted time and $. two things I like to avoid. (I wasted 10 hours and $100 last week.)

It sounds like the ICM is going out, when it does, it usually results in multiple random misfires.

I would clear the codes again and see if they come back to cylinders 3 and 4 again. If they do, move coil 3 to cylinder 1 and see if the misfires fallow the coil pack. If the misfires are still coming up random then it's probably the ICM.

DIY test of power output stage/ignition amp module N122 (long & BWW) - AudiWorld Forums

 

thanks for the heads up, here's an update:

-Unplugged the ECU for ~20 minutes
-Car started fine, no CEL, less rough idling
-Let car sit for 5 minutes running (idle)
-Test drive was 95% better, still not 100%
-No boost (from what my bluetooth obd2 -> android app tells me)

 

I'm not sure how you are measuring boost through OBD2 since the ATW does not have a MAP sensor. Do you have a boost gauge?

 

No, it was on my to-do list before this CEL fiasco. VAG-COM comes in a couple days.

Using the app (Torque Pro) it has 3 options for reading boost:
-Prefer MAP (Default)
-Prefer MAF
-Prefer ALT
It was on MAP, I'll change it and see if anything changes.

 

It won't. And VCDS won't be able to help you out there either. You need to get a boost gauge to properly monitor boost/vac. What kind of numbers was this app throwing at you?

You could do a boost leak test to try and find a possible leak. Otherwise drive the car and see what codes come back and do the coil pack swap. Wouldn't hurt to throw new plugs in, they're cheap enough.

Is the car chipped or stock?

 

Stock.
Drove the car again, running like crap. Misfire CEL, nothing when I scanned it a couple minutes later (light went off)

When you say plugs do you mean the coil pack or spark plugs?

thanks for the responses btw, not being able to drive sucks!

 

Boost gauge app is is reading between +4 and -23 for the boost... lines up with limp mode, no?

 

Spark plugs.

Yes, those numbers would be indicative of limp mode (5psi). -23inHG is correct for vacuum as well, though I'm at a loss on how the app is figuring those without a sensor. You should still get a mechanical boost gauge.

 

The VAG-COM (Lite, apparently I purchased the wrong cable) shows that I'm misfiring on "random cylinders"

When I drive it it's not terribly bad until I hit the really high RPM range then boom, misfire. Still idling rough.