Any Caterpillar experts here?

Hello everyone,

We recently purchased a 1998 Tradewinds on a Freightliner chassis. It has a Cat 3126B engine. Drove great on the way home and ultimately suffered a high pressure oil pump failure shortly thereafter. I replaced the pump and all filters. Once I got it started I had flash codes 72, 73 and 74 present which are injector driver codes. From what I read that meant reman ECU. I found a place to reman my ecu. They found some failed capacitor on the circuit board pertaining to the injector circuits and replaced them. I got the ECU back and it starts the engine but now I have codes 15, 25, 27 and 32. These are all sensor codes, 2 of which result in a low power operating mode. I sent the ECU back as it seems to me like the regulated sensor supply voltage could be an issue. They told me codes were not active but they cleared them.

Haven't received the ECU back yet but I'm hoping someone with more experience than me can help figure out why the engine starts and runs fine but does not make much power anymore. The injector control pressure regulator was replaced with the pump. Where do I need to be looking?

Thanks in advance.