I changed the battery and the ECU computer shows the check engine light and the engine misses under acceleration. How do I reset the ECU myself without a computer? Will it reset by itself and how long will it take?
Jim

 

Resetting the ECU usually just requires pulling the battery and touching the terminals together for like 10-15sec.

The terminals from the car, not the battery terminals themselves, in case that needed clarification

It sounds like you are having a voltage drop causing your spark to blow out or just not ignite the mixture fully.. make sure the terminals are making good contact on the battery its self.

Autozone can pull the codes for you to determine what the problem is if tinkering with the contact surfaces doesn't resolve the matter.

 

I've disconnected my battery lots of times and never had to reset my ecu. Is it the stock battery? I noticed that when I tried an aftermarket battery that the posts on the new battery were not raised off of the top of the battery like they are on the stock one which meant the terminals didn't clamp tight enough. I don't know.

Good Luck

 

When you disconnect the battery you reset the fuel trims to default. The car wont pass emission until all 5 emissions codes are rebuilt. Your car will still run but starting from default settings and with the degrading sensors it might not be as efficient.

 

It wont reset the DTC code but reset the fuel trims if you disconnect the battery. You need a scan tool to read codes and reset them from the port under the steering wheel.