Hi everyone,

I have an 1996 Audi A4 (B5) 1.9TDI @ 164,000 miles and have had a few issues recently with the "limp" mode problem. Within the past few weeks though things have got worse and I now suspect that the issue may be something other than the MAF.

A quick summary of the events recently include noticable power loss going up hills, inability to push much past 70mph (overtaking only of course!!), a change in the sound of the engine, Coolant temp won't go above 80c and then much more concerning is that the car has started to spit out some smoke during hard acceleration.

At first the smoke was black although after putting in an injector treatment I would now say it is more a white smoke. The treatment restored some power but I knew something wasn't right. I got myself a VAG-COM cable and hooked it up to the laptop and discover a few faults including the following:

Address 01: Engine
Controller: 028 906 021 CE
Component: 1.9l R4 EDC 00SG 0803
Coding: 00002
Shop #: WSC 06325
1 Fault Found:
00575 - Intake Manifold Pressure
17-00 - Control Difference

I decided to then log some data during a short run in the car and I notice a few strange trends, including the EGR valve. Please see the graph below.



I am not too sure where to start and would appreciate any advice on how to proceed with identifying the root cause of my problems.

Thanks
DJJoker