1996 saturn sl1
 

I have a couple of problems
I keep having a a p0401 egr flow insufficent detected.... I replaced and cleaned the egr valve and sensor. the tach shows it idles low.. around 400 but when i hook up a scan tool it seems to be idling ok... the car vibrates until it is warm.

Now i am getting the same code and p1640 quad driver module malfunction
and p1641 quad driver module malfunction and a p1620 low coolant when I dont have low coolant...although i do smell coolant when i put my heat on.

ANY HELP IS APPRECIATED!!

don' t think an s car can idle that low (what did the scanner say the rpms were?

Quad driver faults are almost never the quad driver but instead something monitored by the circuit -- which is a bunch of stuff

Based on the EGR code, I'll venture to guess it is an issue with the EGR solenoid not modulating the EGR position correctly since you've already cleaned the EGR

i have replaced the egr sensor when i cleaned it....

a solenoid is a device not unlike a switch.
don't know what you mean by egr sensor unless you mean solenoid

Also you indicated you "replaced and cleaned the egr valve and sensor".

Which is it? Cleaned or replaced?

ive cleaned the old one and then i replaced it and i still have the code i cleaned out all the ports well when i changed the motor.