Hi
The majority of EGR valves are located on the manifold,when a fault occurs with the EGR the valve may not be the problem quite often it is due to a split or perished pipe on the EGR so it is advisable to check the vacum pipes first.
Hope this helps with your problem
22L (liters) is 5.81 US gallons.
Rear of the engine block.
Ther is no egr valve on the 2.2 turbo engines. With FI and turbo, there was no need. Some of the earlier carb engines did have egr.
I changed the EGR valve, PVC valve, now it has gotten worse. I also cleaned the throttle body.
Start at the radiator and follow the upper rad hose to the engine. The hose connects to the thermostat housing. The thermostat is located in this housing.
97 chev cav fuel filter is located in under rear passenger side right by the wheel axle.
it is next to the coils at the rear of the engin between the tranmission and the engin
lr stands for long rifle(uses a bullet) I dont know where you got 22l from
Impossible to answer without more information
50-200 usd
10-1000 USD depending on specifics.
20-50 or so