968Forums.com

Not related to the 968, but just in case this could also happen to our cars I thought I'd share the story :

The "service engine soon" light came on in my son's Altima and the ODB identified the only fault to be

" Fuel-Air metering " . The car has fairly new O2 sensors, so I ruled that out and searched the Nissan forums for another possible cause. The majority of the answers pointed to , of all things, either the thermostat , or the temp sender unit ! It seems that if the cooling system does not reach the correct operating temp ( 195 F for Nissan ) the computer is also unable to set the fuel-air mixture right, and it triggers the CEL . Wonder if this could happen to our cars also, or it's an entirely different technology that applies and that's not a possibility with the 968 CEL going off from that.

that is an emissions thing. all cars run cleanest when the air/fuel temp is at 195 degrees f (though not necessarily making the most power). that is why thermostats are what they are. the computers in cars today adjust things when it is colder or hotter. this can be done by a number of methods, but in your case, it uses sensors. if those sensors aren't working properly, the computer freaks out. on our car, it is usually the MAF.

One more reason to drive cars from an era when computer management systems did not exist....for example my MBZ's computer throws the car into the lowest gear limiting it to that speed if the battery voltage drops below a given level, and you cannot override that so if you happen to be many miles away from your destination, you're SOL, better get used to driving 20 mph all the way ..or stop somewhere to replace the battery. Also, when the coolant temp was not right because of a bad thermostat ( MBZ again ) it acted as if the transmission was slipping, so it scares the crap out of you, thinking a $ 7,000 repair is coming up.. WTF is it with all that technology crap they load on these cars ?!

lol - on top of that, mbz adheres to the idea that if one computer is good, multiple computers must be better. in the SL550, there are something like 6 of them, each like a "department head". they all have to work in unanimous agreement too.