Q: Can using the wrong oil filter cause the oil pressure gasket to leak?

If the check engine light came on, and the light was still on at the time the mechanic did the "diagnostic", it is impossible for there to "be nothing wrong". In particular, the check engine light will only illuminate if specific, downloadable diagnostic trouble codes have been stored by your vehicle’s PCM. Using the wrong oil filter will have absolutely no effect on the oil pressure sending unit or the seal, if gasketed, to the engine. However, using the wrong engine oil filter can result in an oil leak, and possibly loss of all engine oil (with catastrophic consequences), if the rubber seal on that wrong filter does not properly coincide with and seal on the oil filter mounting base on the engine block. Should you desire a diagnostic on the oil pressure switch please request a switch diagnostic. You can also schedule oil and filter changes at your location by contacting YourMechanic(https://www.yourmechanic.com). Please let us know of any further concerns or questions that you may have.