Isuzu Repair: 96 Rodeo - Check Engine light on and trans slipping, fuel sending unit, light auto

Question
I bought this truck new and the only time I've had this light go on is when I've bought bad gas. It usually goes out after i fill up again but is there a better way to check if something serious is happening? Also, 2-3 gear shift is slipping on occasion. Is there a fluid additive or something that could help with this?

Answer
Hello, mike, I would check on your fuel sending unit being bad, Also, Get your transmission flushed and refilled with a new filter with some additive, this will most likely fix your tranny problem, As the Check engine light, Auto Zone checks codes for free.