98 sls power problem
 

Just had a used motor put in my car and trying to work the kinks out. The service engine light has been coming on. I had the codes read at autozone and it it detected a rich or lean air/fuel ratio on engine bank 2. probable cause maf sensor, heated oxygen sensor- bank 2 sensor 1. or ignition misfire, fuel injector problem, engine mechanical condition. I found the line running to map sensor was busted and leaking, fixed it and car is running pretty smooth, but light still coming on and now i have no power. It won't spin tires from a dead stop and passing gear wont kick in at any speed. Acts like a 4 or six cylinder and just goes faster. Could bad oxygen sensor cause this to happen. Also keep in mind i accidentily got some coolant inside the connection on the throttle idler module (on side of throttle body) and had problem with the idle, causing it to run real fast at times. this lasted a few days until i cleaned it. The idle is real good now and car runs real good to but still no power. Please help. I also changed the maf sensor. i put the old one from the old motor on yesterday.