Just recently solved my Slow Down 1-4 light (not turning off). Cheap fix! What I have: -1990 Mondial t cab - Aftermarket muffler, removed cats, fitting for thermocouplers in straight pipes What I did: 1) Cut the wires (2) between the ECU and the Thermocouple on the 1-4 side. 2) Solder in a 20 ohm resistor (2 bucks). Makes the ECU think everything is fine! No more Slow Down light.
