Greetings.
My check engine light has come on twice just lately with the code 13. My manual says it's Map pneumatic signal or MAP voltage too low. Does this indicate the MAP sensor needs to be replaced? The oil pressure has been dropping with this new problem, don't know if it's related at all. Any suggestions? Thx!

 

The Map sensor is located on the passenger side of the throttle body, under the air cleaner. There is a vaccuum line running from a port on the bottom/ back of the TB to the map sensor. Make sure this vaccuum line is not leaking. If I disconnect mine, the CEL lights instantly.

I don't see a relationship between the map sensor code and the oil pressure unless you've got serious internal engine problems.

 

A MAP sensor has nothing to do directly with oil pressure. Perhaps the 5 volt wire powering the sensors has a problem and is not providing full power to the MAP sensor or the oil sending unit.

 

Thanks to you both. I will check the vacuum line and then the wire and go from there. Is there an oil pump or oil sending unit that may be going bad causing the pressure to drop?

 

2 causes of actual low oil pressure are worn bearings, or a worn oil pump.

The sending unit only senses the pressure and sends a signal to the gauge.

 

okay I checked the vacuum hose and I didn't find a leak. I also unhooked it while the van was running, the engine stops at that point. The wiring still looks good but I don't have a way to test the voltage. I'm thinking maybe the MAP sensor is going bad. The oil pressure could be related to the cold weather here and there is Lucas added in. I'll take it in to the shop I guess. Thanks!

 

Colder weather means slightly cooler and thicker oil at full temp which would translate into higher oil pressure. Lucas is very thick and also increases oil pressure.

A shop will be able to put a mechanical gauge on and test the pressure and determine of the sending unit is bad, or you actually have low oil pressure.

The vaccuum port where the map sensor vacuum line connects is prone to carbon build up.
If the throttle body has never been removed and cleaned. It is possible the port to the map sensor is filled with carbon, not allowing the Map sensor to read intake manifold pressure and lighting the CEL.

It is not very difficult to remove and clean the TB. The little port on the back where multiple lines run to, comes off with 3 torx bit screws. But there is a gasket which most likely tear upon removal.

I know this suggestion might get Alloro all riled up, especially with you being female and all, but pull the vacuum line off the Map sensor and see if you can easily suck or blow air through it with the other end still attached to the throttle body, to determine if it is clogged and if a TB removal and cleaning is necessary.

The only times I got a code 13 was when my ECM was failing, and causing the engine to sputter, stutter and backfire.

Harbor freight sometimes sells a digital multimeter for $2.99. Regular price $7.99. It's not a professional tool, but I've tested mine against an 85$ Fluke meter and found it to be pretty accurate. It is very worth having one.
http://www.harborfreight.com/cpi/cta...emnumber=90899

Good luck. Is your overdrive working?

Here's a mechanical oil pressure tester for 10$ while your at HF.
http://www.harborfreight.com/cpi/cta...emnumber=92687

 

Naw, only if she lived near me!

 

You guys are too funny! I'll blow on the vacuum hose and have the shop test the pressure of the sending unit. I'm fairly certain the TB has never been cleaned. I've only cleaned what I could get to easily. Still no OD, the next step is a tranny shop recommended by the new mechanic. The flywheel cover is missing, I have no clue why. My endless budget for this van ran out! LOL

 

You know...if you do that in front of them they might not charge you to test the sender.