I have 2004 SLE with oilpressure guage spiked at 140. Is sensor bad or is there something else?

Replace the oil sensor. Everything should be fine.

I agree with Dan. If the oil is reading at 140 oil would be spraying out when the oil cap is removed. If this the case KILL THE ENGINE and change the sender and censor. I had mine changed, mine being the censor, and it was fine. Good luck.