My power steering is bad when I'm trying to park Or when the rpm's are under 1000 if I'm in park or neutral and I step on the gas and go over 1000 rpms the steering is normal like it should be... Also every time I open the reservoir like to check the fluid it let's out pressure when I take the cap off it sounds like when you open a soda can... I've been told three different things by three different mechanics...

try to increase the idle-rpm..
Example - at standstil condition when you start your van, have look at rpm... say 1000 or 1200 or 1500.. whatever it may be..
Keep idle-rpm a little bit higher, if previously it was 1200rpm then set it to 1500 rpm..
If the problem is solved then..
1) clean ur airfilter
2) check spark plug condition
good or bad... if bad then replace..
3) check fuel supply line, if it is damaged or folded

Check for vacuum leaks. With the rpm difference that large it should be pretty easy to hear the vacuum leak hissing with the engine running.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

check the fuel pressure regulator and the map sensor vacuum hoses. as for the not revving above 4000 rpm is what the computer limits the engine to with no load on it, like in park or neutral.

EGR (exhaust gas recirculation),or TPS (throttle position sensor) When the vehicle makes a stop and go into idle. The RPM is basically too low to maintain the RPM, If the vehicle runs 800 RPM in park or neutral and doesnt stall the setting is correct. If it stall in neutral or park and has a hard time accelerating you will need a TPS, The EGR can stall a engine if it stays open underload approching a stop where it doesnt close properly

SOUNDS LIKE A VACUM LEAK OR A HOLE IN YOU AIR INDUCTION TUBE ( BIG BLACK FLEX PIPE) BETWEEN MASS AIR FLOW SENSOR AND MOTOR

I don't really know where they should be in idle on your car, but if you don't apply your gas pedal, the RPM's should be low. My 18 wheelers RPM's are down to 500 in idle position and go up to 2300 when I step on my "diesel" pedal. If in neutral or park and you step on the gas...do your RPM's go up? If yes, all should be okay.

give me the trouble code once u have it tested.

Surging is often caused by a bad sensor in the air/fuel supply - MAP, IAC or TPS. Check for trouble codes (DTCs) using a good code reader.

Check your coils. Make sure that they are working properly.

sounds like your trans linkage needs adjusting.