I have bougth a sierra cosworth 4x4 which was sold to me as having a stage one chip. After changing the standard actuator for a -31 item I tried to adjust the boost.

What I noticed was that anything peaking above 17 PSI the ECU shut down everything. So now I have adjust it to peak at 16 PSI and holding 14,5 PSI and the limiter on the ECU doesn't come in.

But is this a standard chip as on my previous cosworth with standard chip it only could peak at 13,8 PSI most before the limiter came in. (held max was 11,6 PSI).

And if not how does the ECU know that the boost exceeds 16 PSI as it has a standard 2 Bar mapsensor (I think)?

Hope someone (Stu?) can help me with this.

YBJ