fiesta mk6.5 tdci - idle revs - bergs14

Sat at idle the revs will occasionally increase like the throttly is slightly pressed. Depressing the accelelartor deturns it back to the 800. It increases to around 950rpm..... is this an underlying problem??

Egr is blanked off and a sound like exhaust blow but had replacement exhaust except cat. Seems lower on power / accel also.

Thanks

fiesta mk6.5 tdci - idle revs - bergs14

Sorry to bump the thread everyone but any ideas before i take her in for a check and get a big list of things with a bill lol ?

Tia :)