Map sensor reads 15v on both wires and no change when vacuumed. Ok so its bad...... If you ran it staight through to the other vacuum line? Would it run at all? My check engine light mystery may be solved, but other than running a bit rich I never really had any positive in your face symtoms. Another thing that has baffled me is intermittent cut offs only under 40mph. Fairly recent, but I have checked or changed most of the major electrical components associated with such a problem.

 

No wire on the MAP sensor should ever read higher than 5V. You may have the wrong connector plugged in the MAP sensor.

And 15V is a crazy high voltage to read on any wire in your car.

 

I was thinking th same thing since there was no center ground wire. Gotta hit the book and make sure a mechanic did not switch then..... thanks. Ok the 3 pin connector has two wires. Yellow/black and Red/white....... no ground, so middle hole empty. The map has 2 pins. I was gonna put up a picture, but I do not know how yet. I know I am looking at the map sensor, the book shows it in detail as well list the three wires. Its a denso sensor. This is quite perplexing. The other connectors seem to be where they are supposed to be and do not fit anyway? Need to post pics

 

The MAP plug doesn't have a yel/blk or red/wht so I'd guess your looking at something that isn't the MAP sensor.

MAP= yel/red, red/grn and grn/wht

By the colors you listed closest thing I can see is blk/yel and red/yel for the EVAP purge solenoid but thats a 2 pin plug.

 

How can anyone help when you didn't even post a year or model of the car.

Figure out what harness you have head over to ff squad find the ecu pinouts for your harness and go from there.

I don't thhink it has to be any more clear than that right?

 

99 Civic LX. I traced it out off the schematic in my book, taken care of, never mind...