My car is all stock 91 honda civic si. While driving around the check engine light came on. Looked at the ECU and the code generated is 13. What is an atmospheric pressure senor and where is it located?

 

the pa sensor converts atmospheric pressures into voltage signals and sends them to the ecu. the signals then modify the basic discharge duration to compensate for changes in the atmospheric pressure. as to where it is located i'm not sure on that one. i hope sobody else can help you on the second part... good luck

 

Thanks for the info.