Could you tell me the location of atmospheric pressure sensor in my 1991 legacy wagon subaru? a experienced technician said only replace whole ECU. However, I saw some webpage I can set sensor to over 760mmHg. some people know that? thank you very much

guoqing

I belive only the EJ22Turbo models came with a MAP in your generation Legacy. Is this a turbo model? Otherwise you should just have a MAF there by your air box where the air filter goes. Realy easy to tell as there is a black box on top of a metal tube with a plug and wire cluster going to it.

 

RARELY is the computer bad but it IS a possibility. Is your Check Engine Light on? If so you can pull the codes yoruself and it will tell you exactly what it thinks is wrong. Then you have atleast somewhere to trouble shoot from.

The normally aspirated legacies came with an atmospheric pressure sensor to compensate for altitude changes. The sensor is in the ECU, and can not be changed.

 

Just curious, why do you want to modify this?

 

The stock sensor won't output exactly at 760 mmHG, simply because of the reference voltage can vary. In Houston, which is essentially sea level, my barometric sensor reads 752 mmHG

Thank you for your kind help. as for MorganM's suggestion, actually I read the trouble code ,the number is #45, atomospheric pressure sensor,and the engine light is keeping on. So I have a little worry on that. Also ,I appreciate legacy777's words , do you think I need not to care that too much?

Happy new year!

best wishes

guoqing