Hi,

I have a 2006 Dodge Caravan 2.4L engine that had the engine oil pump replaced. After fixing a previous issue with a flex supply jumper, my van runs ok. However on idle, the engine most likely than not, will stop. Diagnosing it with another person, turns out it has to do with the vacuum system-- particularly the plugs (or caps). When I removed one of the caps, it's able to hold idle most of the time-- although will choke most of the time when it can hold idle. When driving (pressing the gas pedal), it's smooth (like normal).

I'm not sure how the vacuum system is supposed to work, what plugs are needed, etc. I got some rubber plugs of varying sizes from AutoZone and tried to plug them but I can not get the van to hold idle unless I remove one of them. What works currently for me (choking on idle but at least can hold most of the time) is the picture attached. Notice the missing plug on the bottom left which I assume needs to be plugged. This is probably what is causing the check engine light too.

Any ideas or suggestions on how this needs to be resolved? Thanks!

 

Update: I went ahead and replaced the MAP sensor with a new one from Oreilly since the check engine light diagnostic gave a couple of codes that more-than-likely point to the MAP sensor and it was an easy swap. However still the same issue-- I need that one rubber cap to be off in order for it to idle (rough) rather than dying. Next suggestion from the diagnostic is the TPS (throttle position sensor). This one is a little harder to replace. But before I keep buying sensors and such, is there a better way to know the exact problem with the current issue I have? Thanks in advanced!