Cylinder Slow Down Lights on my 308

I have a 1981 308 GTSI and there are lights on the dash for cylinder slow down. What the heck are they for? What is a cylinder slow down?

 

For U.S. cars, it is there to let you know that one bank of cylinders has konked out, unsually due to something electrical, and that the car is now possibly dumping unburnt fuel into the cat in the attempt, if not caught, to barbecue both the car and its occupant(s). That being said, in can also be an electrical glitch that gives a "false positive".

 

Do a search for "slow down" and stand back!

As I was reminded here recently, one thing that is very important re the slow down light is that it is supposed to illuminate for a few seconds when you first turn on the key as a self check. If it doesn't do that (mine doesn't) then you cannot believe anything the light tells you. Mine does not self-test but does comes on occasionally for no reason I can determine and with absolutely no loss of power that would occur if one bank of cylinders actually quit.

 

I'm no expert but I can relay what I was told by my Ferrari part guy who has not been wrong thus far. The slow down lights are triggered by a sensor in the cats. When you are running too hard / hot, the sensor sends the signal to slow down so you don't burn things up. If you remove all of the emissions goodies (including cats), these sensors are useless. There are 2 blocks in the foot wells that recieve and send the signal. Assuming you don't need the sensors, you can simply remove the clip in the blocks in the foot well and no signal. Alternatively, you can simply remove the bulb.

Hope this helps.

 

That is correct they are actuated by thermocouples on the cats.
A miss that is letting unburnt fuel into the cats can also light them up.

 

And light up your car! I recently dropped an ignition coil. After only approximately 1/2 mile of driving an already warmed up car, the slow down light came on. With only another mile to go and obviously taking it real slow with one one bank providing power, by the time I got home, less than 3-4 minutes later, with raw gas spilling into the cat, it was seriously I thought about to self-combust and catch the car on fire.

The warning light is there for a very good reason, and I would make sure it works properly, unless of course you like seeing F-cars get seriously toasted.