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Discussion Starter · #1 ·
So i just installed my o/r x and MIL elmiinators the other day and it got rid of my P0420 code and now this just popped up today.. not sure of the problem? could it be faulty MIL eliminators?

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P1131 - Lack of HO2S-11 Switch,

Indicates Lean lean at the end of a test, the system is trying to correct for an over-lean condition. The code is set when the fuel control system no longer detects switching for a calibrated amount of time.

Possible Causes: See Possible Causes for DTC P1130

P1130 - Lack of HO2S-11 Switch Fuel Trim at Limit

The HEGO Sensor is monitored for Fuel Trim at Limit switching. The code will set when the HO2S fails to switch due to circuit or fuel at or exceeding a HO2Scalibrated limit.

Possible Causes:

•Short to VPWR or VREF in harness or circuit or fuel at or exceeding a HO2S calibrated limit.
•HO2S circuit shorted to Ground
•Water in harness connector
•Open circuit
•Corrosion or poor mating terminals and
•Damaged HO2S
•Damaged PCM (other DTCs should be
Fuel System:
•Excessive fuel pressure (stuck fuel
pressure regulator, restricted fuel return
lines, etc.)
•Leaking/contaminated fuel injectors or fuel
pressure regulator
•Low fuel pressure or running out of fuel
(fuel pump concern, fuel supply line
restrictions, low fuel level, etc.)
•Vapor recovery system (stuck VMV, etc.)
Induction System:
•MAF contamination
•Air leaks between MAF and throttle plate
•PCV system / Other vacuum leaks
•Improperly seated engine oil dipstick
EGR System:
•Leaking gasket
•Stuck EGR valve / Leaking diaphragm or
Base Engine:
•Oil overfill
•Incorrect cylinder compression
•Exhaust leaks before or near the HO2S
•Secondary air stuck on

This is where I got this information

Good luck on tracking this problem down.
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