Im having a few faults with my rs1600i the last few days. The car has a fiesta rst engine thats had kms management fitted about 500 miles ago. The cars done arond 500 faultless miles but a couple of days ago it sarted coughing and spluttering when you pull off from standstill or speed up from a slow pace.

Today i noticed the the vacuum pipe wasnt on the fuel reg so i popped it back on and the engine stallled soon as i put it on and every time i started it the car wouldnt idle untill i took any vacuum pipe off.

My question is, is there any way the mapper that fitted the kms ecu could of missed this? I only ask as when i got the car back he told me the turbo was fooked as it would only make 7psi of boost so was wondering if that could cause the low boost?

Also when i pluged the reg back in the misfire was still the same.