Exhaust

Ok so I had bought a mbrp cat back exhaust system. I finally put it on yesterday and it wasn't what I was looking for as far as sound improvement. So I removed just the muffler and connected the exhaust back together with just a pipe ( yes I know it's illegal). My question would be is this going to drop my back pressure enough to cause any problems, big or small?? Some people tell me it's perfectly fine others say it can mess up my valves due to a decrease in the back pressure.

 

Ok and so what exactly then will be affected?

 

What is the break in period on the mbrp? My magnFlow took 700-1000 miles to mellow and come in.

 

Well it didn't say and I looked into some forums where people were saying they really didn't even hear a difference ever. My intake was litterally louder than the exhaust.

 

Dang.