OVP? From my experience, just replace the OVP and you should be fine. I had three OVP replaced. Twice on my W124 300e and once on my W124 E420. Seems like this part last up to and around every 100K. Not bad for such a cheap but important part. The actual fuel pump relay almost never need replacing. Had the 300E for 20yrs with original fuel pump relay, on the E420 I just recently replaced the OVP at 82k.