hi guys my car has been throwing up engine system fault up and it goes into limp mode with loss of power, when i switch it on and off it was going back to normal. Other day after fueling it up the warning message came up and loss of power with black smoke, i tried the on and off thing but still was the same. i read on here it indicates boost leak, but after leaving it parked for few hours its back to normal with no issues ... so bit puzzled as if was boost leak it would not go? ive driven it on motorway and local for few days and its been fine? any help would be appreciated.. ps the egr valves have been already been blanked off.

I'm guessing it's tdv6, if you fill your profile in, it helps us to help you.

Usual culprit is a split in the intercooler boost pipe going to the air intake. Or split in intercooler, or turbo issues. Bodsys Brake Bible
Software Updates Contact me
RRS Timed Heat/Remote kits - Contact me
BAS Engine Re-maps/ EGR Blank EuIII and EuIV
Clock On The Dash/ SNOTM /3Flash / BT Update /Service Reset/Error Codes read\ Gearbox Reset
See it HERE

sorry its 2.7 tdv6 2005 plate.. could it be electrical as its temperamental? like o2 sensor?

Could be many things. Best get the fault codes as a starter as it could be over fuelling or a MAF sensor. Narrow the location down a bit in your profile and someone may be nearby who can scan the cars codes. Bodsys Brake Bible
Software Updates Contact me
RRS Timed Heat/Remote kits - Contact me
BAS Engine Re-maps/ EGR Blank EuIII and EuIV
Clock On The Dash/ SNOTM /3Flash / BT Update /Service Reset/Error Codes read\ Gearbox Reset
See it HERE

im in birmingham il have to get a code check done hopefully solve it

Split inter cooler pipe 61 AB 5.0 supercharged rocket
07 HSE TDV8 with lots of toys EGR removed BAS remap
56 HSE WAS FULL OF PROBLEMS