EGR System: Description

1988 Ford Escort EXP AutomaticSECTION Description

The Exhaust Gas Recirculation (EGR) system distributes small amounts of exhaust gas into the intake mixture. This lowers combustion temperatures due to lower concentrations of oxygen. Lowering of combustion temperatures reduces amount of NOx emissions. The amount of exhaust gas recycled and timing of EGR valve opening are controlled by engine vacuum, exhaust system backpressure, altitude, temperature, throttle angle and engine speed.

Typical systems consist of an EGR valve, vacuum reservoir, check valve, Ported Vacuum Switch (PVS) and/or a Temperature Vacuum Switch (TVS). The following 5 types of EGR valves are used:

  • Backpressure Variable Transducer (BVT)
  • Electronic (EEGR)
  • Integral Backpressure (IBP) transducer
  • Ported
  • Pressure Feedback Electronic (PFE)
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

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

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

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

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