check engine light is on?

This guide will show you how to get the trouble codes

https://www.2carpros.com/articles/nissan-obd1-diagnostic-trouble-codes-and-retrieval-procedure-1984-to-1994

Please run down this guide and report back.

I just replaced one of my bad Injectors and the seals and gaskets for the rest. Well actually my friend did. But it was pulling a code 51 so that's why I repaired it but after installing it the truck runs great but the check engine light is coming on now. Its not leaking any gas from the Injectors. We checked with a multi meter to make sure all the other Injectors were fine and they were. We disconnected the battery to reset everything and the light came back on. The only thing I noticed after the install was after starting the car and giving it a little gas it kinda sounded like a little whistle when I would accelerate but it would go away. So if you could please give me some suggestions I would appreciate it! Thanks.

re check the work and look for any connectors undone or ground wires not connected.

Roy

Thank you I will check it out.