Whats up guys. Just bought an 07 350Z Fairlady last week. Having some issues. A couple days ago I replace all the spark plugs, cleaned both throttle bodies and after I put everything back together the car was not idling right. It goes back and forth from 1100 to 2200 RPMs non stop. Also my gas mileage is really bad now. only about 10 to the gallon. When your driving at low rpms and let off the throttle just a little bit it's really jury. After about 3000 rpms it seems to drive just fine. Took it to Nissan and they couldn't set the idle.They said the ECM was not responding when they performed the following procedures: IAVL (Idle Air Volume Learn), pedal position relearn and closed throttle position, unplugged MAF sensor. They say I need to start with a new ECM which is going to cost $1700! The car was running just fine before i did plugs and throttle body clean. Any suggestions would be much appreciated! Don't have $1700 to spend on something that may or may not fix the problem according to Nissan.