Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
EGR System: Operation: Notes
EGR system on 2.2L carbureted engines uses ported vacuum to control EGR valve operation. The vacuum signal is further controlled by a Coolant Vacuum Switch (CVS), which prevents EGR operation until coolant reaches a predetermined temperature. The CVS is mounted on thermostat housing.
A backpressure type EGR system is used on 2.2L and 2.5L fuel-injected engines. The backpressure transducer measures the amount of exhaust backpressure and varies the strength of the vacuum signal to the EGR valve. The signal vacuum is bled off into the atmosphere when exhaust backpressure to the EGR drops below a calibrated value.
A backpressure type EGR system is used on 2.2L turbocharged engines. The logic module controls vacuum through the EGR solenoid, turning the vacuum circuit on or off. A backpressure transducer measures the amount of exhaust backpressure on the exhaust side of the EGR valve. The transducer varies vacuum signal strength to the EGR valve.
The logic module prevents EGR operation by turning the EGR solenoid off when engine temperature is less than 80°F (27°C) or temperature is more than 80°F (27°C) for less than 7 seconds. The backpressure transducer adjusts the EGR vacuum signal to provide programmed amounts of EGR under all other conditions.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no 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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.