next to the throttle body, toward the firewall side of the engine compartment
Check the EGR value I have had that problem and that's what it was
the egr valve is on the engine, usually on the top near the air filter
I'm not sure what year and model you Cadillac is but a p0404 should be for the EGR valve open position performance. You will need to replace the egr valve if the wires are okay. Hope this is helpful.
The 1991 Geo Metro EGR valve can be located on the air cleaner housing. The valve will be on the back of the housing.
The EGR valve for a Honda EX 1991 is at the top of the engine. It is at the front, just to the left of center.
There is no EGR on the '91
no the do not but some gaskets kits will come wit a egr gasket
Unless your car has California emissions, you do not have an EGR.
top of intake behind fuel rail
on the intake manifold near the throttle body
Could be the idling sensor or the EGR Valve
Driver side in water manifold under EGR valve