If battery was installed backwards & headlights flashed on & horn sounded but now will not accelerate when cranked

What is your question?

Battery terminals were hooked up in reverse when changed battery, positive cable hooked to negative terminal & negative cable hooked to positive terminal. Headlights suddenly flashed & horn blew. Battery was immediately disconnected. After about 10 minutes a different battery was installed correctly & after successfully resetting idle & cranking car noticed no power when tried to accelerate. All gears shift fine, just no power in accelerator to move or even rev engine. There are no throttle control error lights showing on dash, but check engine light is on, which was on prior to battery installation error. Last knew it was due to emissions. Could the entire ECM be damaged or is there any DIY tests to determine such?

What makes this problem better or worse?

Reset idle, it worked but still nothing when press gas pedal

How long has your 2002 Toyota Camry had this problem?

Since battery was installed backwards