Check for previous modifications.
Is the Downpipe OEM or aftermarket? If it's aftermarket then it's most likely been tuned, and with that being said, the Accessport has most likely been unmarried and sold. (BAD)
If the downpipe is OEM, then is the turbo heat shield missing?
Is the turbo inlet OEM or aftermarket? If it's OEM, then check to see if it's leaking at the turbo clamp.
Are the injectors blue or black? If they're black then they are most likely aftermarket.
Is there an aftermarket intake?
There's a lot more stuff to check but these things are the obvious ones.
Also, check the oil level.