A few days ago my oil pressure started acting up, running much higher than usual. I was hoping it was just something simple like a clogged oil filter but that's not the case as I changed the oil + filter this afternoon. 5w-30 synth btw...

Normally while accellerating, around 2500RPM I'm running at about 40psi. With the issue I have now, when I pass 2500RPM while accellerating the OP shoots straight up to around 75. Scares me. I've been changing gears much lower than I used to just to avoid the high pressure. This is obviously not normal, but is it something I should be terribly concerned about? How high is too high when it comes to oil pressure? The car has 115k miles on it and I've never seen it that high before. The car seems to be driving fine, nothing out of the ordinary.

Another related question I have is about the computer's 'service engine soon' codes. The first time I noticed the oil pressure problem the light came on for about 20 minutes, then shut off. It hasn't come on since (2-3 days). Does the computer remember past error codes that can be read even after the light cuts off?

Any suggestions would be helpful! Thanks!