So, I had to replace my ECM and IPDM recently. When I got my 07 Xterra back from a Nissan dealer, the overdrive off light was on. I noticed that the acceleration that I had before was not there. Having to push the RPM's over 2,000 to get it moving. Once up to speed, everything is ok. I press the button on gear shift, it changes the display from D to 4. I am thinking it is electrical issue. Any advice to get my beast burning rubber again?