I had the oil changed but it keeps saying service is due (took my own oil and filters to a local shop). Could not having reset the computer have something to do with it? It’s been happening about once a week for the past few weeks. Oil probably has 300miles on it

 

I went over mileage and didn't notice any change. The service writer said it is a reminder only.

 

It’s just a reminder as far as I know.
Reset it.

 

Yes - just a reminder that has to be reset either via the OBD computer when serviced or you can do it manually. Start ignition without engine (press start without touching pedals). Open drivers door. Press and hold both pedals for about 20-30s. Release. Turn off ignition

That should reset it

 

Just wondering if that’s why I’ve intermittently been getting restricted performance or not. Just landed in Houston will tackle it tomorrow.

 

No. That won't restrict performance. Pull the codes with a code reader to see what's going on

 

This may or may not apply but I have an anecdote:

Our perkins tier IVs (also an English manufacturer) have an absurd procedure to reset the oil life after an oil change. So often the Preventive Maintenance Tech screws up or skips it and I have to go fix it with my laptops. What happens to these Perkins is that it sees a change in viscosity in the oil but wasn't told it has new oil. This causes multiple issues to unfold. Sometimes it throws a pending fault that no one can see and sometimes we get a hard code on the display... oil dilution... when these first rolled out and it happened we were sending oil off to see what happened not knowing the PM techs were screwing up, we thought fuel was getting in the oil. Oil was always fine... what was happening was it was throwing this oil dilution code... when customers didn't stop using the equipment (or it was a pending fault that wasnt diplayed) the forklifts would not do passive regeneration.... which led to the next problem... dpf (diesel particulate filter) soot loading issues... once it got to a certain soot load it would go into limp modes randomly... no idea how many grams the rover cuts out at. We'd have various regen, oil viscosity, and over soot codes and it was causing a mess. Once this was in play, the oil reset could not be done by the regular procedure, I'd have to go out to the equipment, hook up diagnostics, reset the oil life, clear the codes that I could, manually regenerate the truck several times (about 20 minutesthe first manual regen and 10ish for second... get soot levels fro. High 20grams down to 1 or 2), and then see how it was doing... and a lot of times none of these codes were displayed... i could only see them from my diagnostics programs.
good luck... if you have any questions I can try to answer them...