Hi, I'm brand new here. Let me start by saying I have an '03 XC70 with 137,000ish miles on it and last week I had to have the CEM replaced. All has been well until today. On the highway the Reduced Engine Performance signal came on. I got off the road stopped the car and when I turned it back on, it sorta coughed, there was a little smoke/exhaust cloud. When I got back on the road everything seemed back to normal except it seemed to be a little louder when I wasn't accelerating. When I put it in park, the idle sounded normal but when in drive it was louder. Any ideas? I'm about to order a scan tool but I thought I should see what y'all have to say. Thanks!