Remove noise from linear signal
There are a few simple things that you could try:


sliding-window median filtering with an appropriate window size
linear-regression in a sliding window
robust linear regression to the total signal, if you know the signal duration etc well enough


EDIT: Further idea after a comment from OP on another answer

Since you want the slope at 160000 be the same as before (i.e. no flat section in your signal), you could use a robust linear regression technique such as RANSAC with an appropriate number of sample points to analyze/filter your data.