Hi, I have a 05 audi a4 1.9tdi se 115hp and I recently had straight through twin pipes put on, and they sounded well only really hearing a hum from them in the car at about 2500rpm and just like normal exhaust at 70

However, earlier I started to dismantle my egr as my car is low on power so I wanted to see if it was blocked?, took the top plunger like part off and cleaned it with a bit of brake cleaner to take most of it off, didn't have time for intake or anything, put it back on.
And no my car is humming loudly at idle, let alone all the time was wondering if I have broke something while doing the egr.
Very loud in the car and then when I go the back there's just the nice straight through noise

Any suggestions would be helpful my take it to the manew who done the twin pipes tomorrow, hum was starting to annoy me which is why I came on here