1998 Toyota 4Runner high idle

Hey, I have a '98 4runner with a high idle problem. First, I'll give you a little background. I bought this thing cheap with a bad motor. I replaced the motor with a low mileage salvage engine out of a '97. I used the original wiring harness and ecu. Basically, I stripped the salvage engine down to a long block, but I did not replace any of the existing sensors. Anyway, the engine runs fine, but after it warms up, it idles between 1700 and 2000 rpm's. My code reader said that it had a mass air flow circuit malfunction and an air intake temp circuit malfunction. So, hoping that it was just my mass air sensor, I replaced it. Problem is, it didn't fix it. I've checked for air leaks between the air filter and intake. I haven't found any vacuum leaks yet. Any other idea's? It has to be something simple that I'm missing.