Please Help- Problem On A B5 S4

[doront5]

Hey.
a good friend of mine just bought a 2002 s4 -its a euro model that has been upgraded at Hohenster with an rs4 convertion (turbos ecu pipes) , the car dynoed 477hp but lately it has moods sometimes it goes strong like it should and most of the time its dead like there is no boost- we did not hook up a boost gauge - but diagnostic showed that a REAR EGT SENSOR is faulty, also diagnostic showed that boost falls to 0.5-0.6.

any1 here knows what seems to be the problem? the car sometimes kicks the boost back in 3rd after 2nd is dead...sometimes it shuts down at 4th with no boost...

we have no clue whats going on.

please help(its the only s4 in israel so no1 here really knows how to handle it):s4addict:

[BBGT2]

I would start with the basics stuff and make sure all the hoses, intercooler and turbo plumbing is good and not failing. Which includes the vaccum lines, check the Mass Airflow Sensor and its hose(s). Turbo cars are prone to this kind of problem where it simply a air hose or plumbing problem. Also check and see if the car has a overboost protection solenoid. Being that the car has a modified ECM it could be spiking the boost higher than the ECM thinks is safe.

Good luck,

Bajo