ECU Tuning & Fuel Management - Stolen ECU problem!

Hi I recently had my ECU stolen out of my 95 Civic EX. I figured out my engine type and the part number of the ECU type I needed. Found a used one and plugged it in. The car starts but the check engine light is on all the time now. Do I just need to reset the ECU by unhooking the negative battery cable or could this be more serious? It seems like the engine is idling up and down more slightly as well maybe?

Any suggestions would be really appreciated.

it's a P28 ECU
if the CEL is on you either didn't get the right ecu, or it's for the wrong transmission
the auto and manual ECUs are different and the wrong one will throw a code.

Thanks. This has been a real pain in the but figuring out how to replace this. The part number was the one the dealer gave me and it supposed to be right.

What does P28 represent?
What will happen if I continue to drive with this ECU in place?

...The car starts but the check engine light is on all the time now. Do I just need to reset the ECU by unhooking the negative battery cable or could this be more serious? It seems like the engine is idling up and down more slightly as well maybe?

Retrieve the CEL trouble code (see link in my signature), look up the code, and then clear the ECU. Post codes for more feedback.

yeah get the codes and we will help you from there.

The part number was the one the dealer gave me and it supposed to be right.

oh alright, then it must be something else causing it.

Hey, found out the part they sent me was for a automatic 95 DX! I need to drive out to town 2 hours this weekend but I'm kinda freaked out about it now. What do you guys think will happen if I drive with this other ecu?

it'll work fine for driving temporarily

Thanks for the tip. I think I'm going to skip the roadtrip and just play it safe. I've been told the correct part will be arriving Tuesday.

When I get the correct one do I need to reset it by removing the negative battery cable?

i would think that if the new one is brand new it should be just fine how it is. plus, it should already be reset anyway considering it hasn't been hooked up to power yet.