View Single Post
      01-20-2013, 03:28 PM   #6

Drives: AW 135i
Join Date: Aug 2012
Location: Waterford, Mi

iTrader: (2)

Garage List
2008 BMW 135i  [2.83]
When you first start the engine, the vehicle starts in whats called "open loop". This is a feature of the obd2 system in which the engine controls the vehicle in a very inefficient manner that is intended to pollute as little as possible while warming the engine and the catalytic converters up to operating temperature. The engine is run at a higher rpm to accomplish this in less time because open loop is very bad on both gas and power. When the engine rpm drops down to normal (600-700 rpm) the vehicle goes into closed loop, which is the normal operating parameters of the engine.