MAP sensor or Pressure sensor for exhaust backl pressure?

Hi all, I am not sure if I need map or pressure sensor for back pressure. I read somewhere that it should be absolute preesure but now I cant find it.

Hi,

I use Honeywell MLH (either 50PSIG or 100PSIG) sensors for EMAP usage as they have stainless internals so are more capable of handling the temperatures and aggressive gases found in an exhaust stream. A lot of the common MAP sensors will fail quickly if exposed to these conditions.

It is highly unlikely that you will see a pressure below ambient in an exhaust system, so you do not need to use a absolute sensor.

Thanks BlackRex