i need to replace my damaged ecu in my 01 integra ls, all i'm finding are 96-99 p75 ecu. so my question is will a 96-99 obd2 p75 ecu work in my 01 integra ls 5speed?

 

No a 96-99 OBD2A P75 ECU will not hook right up. You'll need a OBD2B --> OBD2A conversion harness, which you can get off of eBay for about $75 I think. OBD2B has the immobilizer in it as well as a different 4-plug connector whereas the OBD2A only has a 3-plug, so that is the reason you would need the conversion harness. The ECU will work fine and everything though, you just need the harness for it to hook it up.

I put a 96 LS ECU into my 2001 Integra when I did the auto to manual swap and it works 100% fine. Also from my understanding of OBD2B ECU's you cannot just get another one since it won't be compatible with the immobilizer that is in your ignition. For it to work properly, you would have to get the ignition and OBD2B ECU in a pair. I don't know if that is correct though, but it does make sense.

 

is there a way i can tell the difference of an obd2a and obd2b by just looking at it? are there any appearance features that make them differ?

 

Yes, on an OBD2A ECU, the 1st, 3rd, and 4th plug will be used while the 2nd one is blank. On an OBD2B ECU, the 1st, 2nd, and 3rd plug are used while the last one is blank. So you can see the difference, here are a couple pix..

OBD2A ECU plug layout..



OBD2B ECU plug layout..

 

Where are you finding the 96 to 99 975 ECU's at i need one to pass emissions