01 Exploring the Inner Workings of Engine Pistons: A Complete … • 02 How to Drive Safely on Slippery Roads: A Comprehensive Guide • 03 How to Change a Car Tire • 04 Beginner's Guide to Operating an Excavator: Step-by-Step Ba… • 05 Diagnosing and Fixing Noisy Car Problems • 06 Is WD-40 Good for Car Locks? The Truth Revealed • 07 12 Luxury Cars Owned by Footballers That Cost More Than a P… • 08 Never Test an Alternator by Disconnecting The Battery. Here… • 09 The Secret Role Of Oxygen Sensors And How They Quietly Wast… • 10 This Secret Driving Habit Can Quietly Destroy Your Brake Pa… •

DTC codes / Toyota codes / P1661

P1661 · ToyotaEGR Circuit

P1661 on Toyota vehicles indicates that the engine control module has detected a fault within the exhaust gas recirculation (EGR) circuit, which controls the flow of inert exhaust gas back into the intake to reduce combustion temperatures and nitrogen oxide emissions. The computer monitors the EGR system's electrical circuits and flow performance, and when the signal from the EGR valve position sensor or the commanded current to the EGR stepper motor does not match expected values, it stores this code.

SystemPowertrain
Code typeToyota specific
SeverityMedium
Fix difficultyIntermediate
AreaComputer and output circuits

Guidance is general and written for Toyota vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage