My '99 A4 V6 started developing a rough idle, but seems fine while accelerating. The CEL turned on, i plugged in Vag-com and it shows:

11 Faults Found
17549 - Load Calculation Cross Check: Implausible Value P1141 35-00

16684 - Random/Multiple Cylinder Misfire Detected p0300 35-10

16685 - Cylinder 1 Misfire Detected p0301...

Repeates for Cyinder 4 twice, cy 5 twice and cy 6 twice

Then: 17535 - Fuel Trim: Bank 1 (Multi): System Too Rich P1127

Any ideas on what could be going on? the guy who sold it to me said he replaced the MAF recently, and it looks replaced, also aftermarket filter was put on. It did not act like this when i bough it, only after about a month of driving it.

I tried clearing the Codes, and once got all this plus O2 Sensor B2 S1 Malfunction in Circuit, EVAP Emission Control SYS Small Leak and Secondary air Injection System Incorrect Flow Detected.

 

MAF problem?

vac leaks?

coil packs?

if the MAF was just replaced, look for vac leaks

 

I guess i would lean more towards coil packs since it just started randomly developing the problem recently. Is there a way to test the coil packs without replacing them with good ones

 

swap em around and see if the misfire follows

 

30v coil pack is a combination unit and can't swap around like the ones with coil-on-plug ignition. Load calc error deals with fueling - it comes from MAF, O2, TPS, CTS, and other sensors. You can do a throttle alignment and see if that helps. Being that you have misfires on each cylinder in bank 2 (driver side) you may have a cam sensor issue or a belt that jumped a tooth on that cam.