1987 Cadillac SevilleFACTORY OEM SERVICE PROCEDURE

Closed Loop Fuel Control

The closed loop fuel control system maintains an air/fuel ratio of 14.7:1. The O2 sensor monitors oxygen content of exhaust gases and sends the information to ECM. The ECM, in turn, corrects air/fuel mixture for deviations from ideal ratio.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.