023F Intake Manifold Pressure Control Difference - Looking for advice plz

[Passatbloke]

HI folks been doing a bit of research but bear with me.

Passat 1998 TDI (Red I in TDI on the back) 172k miles

Recently losing power on motorways and uphill or under load - 2.4 - 3k rpm feels like no boost

Local garage diagnosed 023F intake manifold pressure Control Difference as error code

They checked all the hoses and seemed fine, Diaphram ? fine, removed and cleand MAP and MAF sensors.

Not sure what diagnostics they used but readings are:

Air mass nominal 290.0 mgs
Air mass actual 285.0 mgs
Boost pressure nominla 1020 hPa
Boost Pressure Actual 999 hPa

They are just a general garage not VW or Turbo specialists. They have advised either sticking vanes (sooted up) Boost control valve issue or VNT actuator issue.

Reading up on other posts I see it could possibly be one of the sensors knackered even though its been cleaned.

NO sign of heavy smoke and resets itself once ignition turned off

I am not really a spanner man so its getting into un charted territory for me.

Any views or thoughts on this or those reading ? Is it worth splashing out on a VW or turbo specialist or worth replacing one or 2 of the sensors themselves first ?

Its serviced yearly inc fuel and air filters and is standard. Any help welcome as need to keep the old girl running for at east another year.

Or anyone recommend Telford or Shropshire area decent place to take it to.

Thanks in advance for any help

[martin1810]

The diagnostic readings don't tell you anything. Your fault code is usually caused by coked up turbo vanes but can be other things. You really need another code read to get all available codes. You need to know if you have under boost or over boost. You probably have over boost.