1993 Lexus ES 300 Leaking gas from tailpipe, engine floodin

I had the same problem once, check the following:

you might have a shorted injector
You might have a faulty ECM as a result of a short in the wires that come from the ECm and connect to the injectors.
Your best bet is to check all the wires first to see if you have a short in the wires , then check the injectors and last look for an ECU - ECM

I hope this helps.

Doxeng