The A20A 86-89 Accord PJ0 ECU had many revisions in different countries. Some of them will lack an O2 sensor or EGR control. However, they all use a vacuum advance distributor.

The A20A 86-89 Accord/Prelude PJ0 ECU had many revisions in different countries. Some of them will lack an O2 sensor or EGR control. However, they all use a vacuum advance distributor.

The California Emissions PJ0 were OKI 80C154 based and always use a 256k External ROM

The California Emissions PJ0 were OKI 80C154 based and always use a 128k External ROM

%META:FILEATTACHMENT{name="PJ0-666-front.jpg" attr="" comment="USDM 86-87 Prelude SI PJ0 ECU" date="1167423731" path="G:\website\ecu\PJ0-666-front.jpg" size="797657" user="carotman" version="1.1"}%

The A20A 86-89 Accord PJ0 ECU had many revisions in different countries. Some of them will lack an O2 sensor or EGR control. However, they all use a vacuum advance distributor.
Most those ECUs were made by Matsushita. Some of them use an external ROM.
The California Emissions PJ0 were OKI 80C154 based and always use an External ROM

The A20A 86-89 Accord PJ0 ECU had many revisions in different countries. Some of them will lack an O2 sensor or EGR control. However, they all use a vacuum advance distributor.

Most those ECUs were made by Matsushita. Some of them (86-87?)use an external 128k ROM.

The California Emissions PJ0 were OKI 80C154 based and always use a 256k External ROM

%META:FILEATTACHMENT{name="PJ0_L022.JPG" attr="" comment="California Emissions PJ0 ECU. OKI based" date="1139439318" path="PJ0_L022.JPG" size="212536" user="carotman" version="1.1"}%

%META:TOPICINFO{author="carotman" date="1138604640" format="1.0" version="1.1"}% The A20A 86-89 Accord PJ0 ECU had many revisions in different countries. Some of them will lack an O2 sensor or EGR control. However, they all use a vacuum advance distributor.
Most those ECUs were made by Matsushita. Some of them use an external ROM.
The California Emissions PJ0 were OKI 80C154 based and always use an External ROM

%META:FILEATTACHMENT{name="PJ0-A03.jpg" attr="" comment="Canadian 89 Accord ECU. Made by Matsushita" date="1138604084" path="PJ0-A03.jpg" size="282684" user="carotman" version="1.1"}% %META:FILEATTACHMENT{name="PJ0-604-2.JPG" attr="" comment="EDM A20A4 no EGR and no O2 sensor from an 89 EX-i" date="1138605222" path="PJ0-604-2.JPG" size="588048" user="carotman" version="1.1"}%