Golf IV / Jetta IV :: 2003 GTI 1.8t Timing Belt Broken?

I recently purchased 2003 gti with a broken timing belt i bought a reman cylinder head did the timing belt, water pump, belt tensioner, cam chain, and cam chain tensioner. I read the service manual and many forums before setting the timing. I got it all set and back together it runs great at the low end but it feels like when it starts to build boost pressure it stops making power. Would i throw a check engine light if the timing was any off? Would it run well on the low end and then lose power if the timing was off or should i be looking in a diffrent direction? I just want to make sure timing is not an issue.