ecu identity

I just recently purchased an ecu for my GSR on ebay. The guy had very good feedback and had been selling on ebay for a few years. He advertised the ecu as "Chipped P72 OBD1 GSR VTEC ECU". But when I recieved the damn thing it said P75 on the shell. I called him up and asked for a refund but he told me that it was the same exact thing as a P72 because when he chipped it he also changed the main internals. It runs very well with my car but my question is, is his statement really accurate? Will this ecu be the same as a P72 if he indeed changed the internals?

basically you are using the 95 ls ecu. if you do, you should have lost the secondary intake runner. if he changed the internals, that is a different story.

What's a secondary intake runner? And are you saying that it is possible for somebody to change the internals? One more thing. Before I swapped to this ecu my check engine light would go on after 6,000 rpm or so and I would throw a knock sensor code. But now I don't get that code.

it should be fine if he chipped it correctly. the p75 can be chipped and ran on any external rom. it can be easily converted to run on a gsr or any other vtec motor. it will not be a true p72 because it does not have a knock board.

you should have fixed the code 23 knock sensor. just because the p75 is on, doesnt mean the problem is gone ;) throw the original p72 back on and take care of the code.

Just like he said, any OBD1 P75 can be converted to be identical to the P72 minus the knock board.

You probably had issues with your knock sensor before swapping the ECUs. Since a stock sensor isnt any good over ~4000rpms I personally wouldnt worry about now that you have an ECU with no knock board in it, you wont throw that cel and the knock board cant pull timing.

However, if there is a problem with your engine knocking at those high rpms, you will soon find that out.

Thanks for all the help. Now that I have this new ecu I've been reving up to like 6 or 7k with no problems. I mean I shouldn't. I just had the whole engine rebuilt and I only use 91 octane gas. But what exactly would it be like if my engine was knocking excessively? It shakes pretty bad but only when I'm at idle.

I have brand new motor mounts and polyurethane inserts holding my engine in. Do you think maybe that's why it shakes so bad?