DTC P1127 Audi
Long Term Fuel Trim Add. Air. Bank 1 System Too Rich
Long Term Fuel Trim Add. Air. Bank 1 System Too Rich
Description
Engine started, battery voltage must be at least 11.5v, all electrical components must be off, the ground between the engine and the chassis must be well connected, the exhaust system must be properly sealed between the catalytic converter and the cylinder head, and the oxygen sensor heater for oxygen sensor before the catalytic converter must be properly functioning. The fuel mixture is so rich that the O2S control is on lean limit. Note: After exhaust system repairs, make sure exhaust system is not under stress and that it has sufficient clearance from the bodywork. If necessary, loosen double clamps and align exhaust pipe so that sufficient clearance is maintained to the bodywork and support rings carry uniform loads. Do not use any silicone sealant. Traces of silicone components which are sucked into the engine are not burned there, and they damage the oxygen sensor.
Cause and Solution
MAF sensor circuit open
MAF sensor circuit shorted to ground
Air leak in the manifold
Secondary air injection system combi-valve stuck open
Secondary air injection system electrical short
Fuel pressure too high, leaks in the vacuum hose to fuel pressure regulator
Fuel pressure regulator has failed
Fuel injectors are dirty, faulty or do not close properly
Video Guide
Diagnostic Info
- DTC Code: P1127
- Brand: Audi