Any help appreciated. - just change the MAF due to a fault code showing the MAF had died, replaced with a cheap - very cheap ebay item (£30 new)

now I'm getting a P0046-00 - Turbo/supercharger boost control solenoid - circuit range/
performance

the car run okay with the bad maf, a bit of black smoke on hard acceleration, but otherwise was good.
after replacing the MAF I'm getting the above code, and car is in limp mode.


Any ideas, obviously the new maf is effecting something, i don't think its a bad solenoid as it boosts fine with the bad maf.
could it be a split pipe?

thanks in advance.