need help with fault code

[focusdarn]

my engine man light came on and found the fault code and this is what popped up.

p1518 imrc stuck open b1

can sumone please help me with this as i have no idea what it could be, i have my dreamscience already on my car and this has only sprung up recently, i have a decat but the dreamscience takesthe lights off or that. i jst had my car serviced new plugs and leads and oil and filter etc.. but my fuel filter wasnt changed. could this mibi spring the light up, i am gettin a misfire every so often aswell and i am assuming this is all related.

thanks

darren

[focusdarn]

P1518 - Intake Manifold Runner Control Malfunction (Stuck Open) The IMRC system is monitored for failure during continuous, key ON engine OFF or key ON engine running self-test. The test fails when the signal on the monitor pin is less than an expected calibrated range at closed throttle. IMRC monitor signal circuit shorted to PWR GND or SIG RTN

Damaged IMRC actuator

Damaged PCM

An IMRCM PID reading approximately near 1 volt at closed throttle may indicate a fault

ok i found out wot the code means but could sumone explain this alot bette please as im totaly lost with this and what damage can be done and if its going to cost alot to fix.

cheers

darren