Hi I recently brought a 2003 A4 convertible 2.5TDI and have a limp mode problem so far maf and map sensors changed plus valve on bulkhead (dont know what its called) mr muscle to the turbo twice particulte filter cleaner put through the system and cat cleaner every one of these items have made improvements but I seem to be skirting around the fault (0575) running out of ideas can anyone help