After work I was changing the oil in the 1970 220D. everything was going good, I put the oil filter in the canister, put it back on the engine, drain plug is in, I put in 1 gallon of oil, went to grab the other container of oil and I see the Pre-Filter still sitting on the old oil filter. I am assuming I am not the only person that has done this.

Does any body know if it will be ok to leave it out in till the next oil change?

Thanks
Kevin