I've been having trouble with my van as of late. It seems that whenever I shift quickly from drive to park it stalls and it also will sometimes stall when in reverse. I have also been noticing a fluctuation in the oil pressure (according to the gauge). Does anyone have any idea what my problem could be?

What size engine ?

I agree we need more info.

When does it do it cold, warm?

Shifting quickly from drive to park??? Explain

How is cold start up.

The van has a 3.3L V6 engine. I know for sure it stalls in reverse when cold, but haven't really noticed in drive. What I mean by shifting quickly from drive to park is if I stop and don't shift through every gear (Neutral, Reverse, then Park) it stalls. Hopefully that's enough info, if you need anything else let me know. Thanks for the replies :)

I would remove and clean the throttle body with throttle body cleaner. While you have the throttle body off remove the IAC and clean the port for it too. Clean the IAC best as possible but DO NOT spray the unit with cleaner as it will damage it. I am thinking that the carbon build up is your problem.

Friend of mine has the same vehicle, engine and it was stalling while cold when turning corners and such and I cleaned the above and switched the IAC from another vehicle and the problem no longer exists.

Have you done the key dance for any possible codes? Is the CEL on?

In case you are unaware of the key dance it is: turn ignition switch to run position withoout starting engine, on/off, on/off, on . The CEL will flash pause flash, flash = code 12. Post codes.

Keep us posted.

I will check for the codes when I get some time, I'm a little busy lately so it may be a little while.
When I go back home in a week or so I will try cleaning up the throttle body and such too, see what will happen.
Thanks for the info.

When you remove the IAC to clean port along with throttle body make sure you disconnect the battery to reset the computer.

I have tried to do the key dance on the van and didn't get any codes. I'm assuming I did it correctly, you switch from run to off, run to off and stop?

Sorry in description of the key dance, I meant to say off/on, off/on, off/on within 5 seconds without starting engine.