I have been trying to get my ECU updated. Are there any aftermarket company,s that sell these? Can the unit in my vehicle be reprogrammed, and if so by who?
As the fuel injection system is mostly mechanical, as opposed to electronic fuel injection (EFI), the W201 is not really "chip" tuneable or expected to gain much from reprogramming the ECU. To gain more power with a reprogrammed chip, you'd have to increase the fuel and/or air being fed to the motor, whereas the standard W201 ECU is just controlling metering the fuel depending on temp, engine load and emissisons.