If a vehicle has an improperly calibrated chip, reduced power, lowered mpg, and poor driveability may result. Generally, these lower mpg and increase exhaust emissions. Some are illegal for on-road usage. Each manufacturer specifies different diagnostic techniques to test for each sensor and for the correct engine calibration chip. Some first generation and most of the latest generation systems use a self testing diagnostic system to detect a non-standard calibration chip.
All vehicles still require correctly adjusted static timing.
In distributorless engines, static timing is accomplished by a crankshaft or camshaft sensor. These sensors must be correctly installed to accomplish correct static timing. Exact procedures MUST be adhered to in establishing this timing reference point. Some manufacturers do provide some checking specifications for timing advance for certain driving conditions. Some use a portable recording device to validate computer operation during specified driving cycles.