Hmmm, well I'm not sure about 05744 but the ODB II- P0574 is a generic code on the Fiat system for.... Cruise control system -Vehicle speed too high
It's the closest match, sounds like the original mechanic was using an old ODB scanner and not an ODB II
Have you a cruise control stalk actually fitted? If so it could be a loose connector or brake light switch.
Personally I wouldn't say it is related to your running issues but a blowing exhaust will certainly have a bearing on performance
Moral of the story is:
Try not to totally rely on just code reading....
Go with simple methodical and logical mechanics and rectify what you "know" to be at fault first....
If that rectifies the running issue, then read the codes and clear them or you will simply end up worrying needlessly about non discript codes and end up chasing ghosts in the system which cost you money (£45 a time) when it ends up being unrelated mate ok.
Hope you get it sorted
P0574 Cruise Control System - Vehicle Speed Too High
OBD Code P0574 refers to:
When the brake pedal is depressed, the stop light switch sends a signal to the ECM. When the ECM receives this signal, it cancels the cruise control. A fail safe function is provided so that the functions normally, even if there is a malfunction in the stop light signal circuit. The cancel condition occurs as battery positive voltage is supplied to terminal STP.
When the brake is on, battery positive voltage is normally applied through the STOP fuse and the stop light switch to terminal STP of the ECM, and the ECM turns the cruise control OFF. If the harness connected to terminal STP has an open circuit, terminal STP will have battery positive voltage and the cruise control will be turned OFF.
Symptoms of OBD code P0574
- Engine Light ON (or Service Engine Soon Warning Light) - Cruise control system inoperative
Possible causes of OBD code P0574
Miss-adjusted brake switch - Brake switch open or short circuit - Poor brake switch electrical connection - Failed brake switch The Error code is generally activated on detection of the following conditions: The P0573 codes is set when there is a malfunction with the cruise control system.