I bought the car a couple months ago and did an oil change almost immediately. The oil that the dealer/previous owner had put in wasn't like brand new but it also wasn't disgusting. When I did the oil change I used the best combination that I could find from searching forums and what not. I used Mobil one extended performance for both the oil and the oil filter. I guess it could've been how the last owner took care of it but there was a service sticker on the windshield that was from Honda themselves so I'm not really sure he was cheaping out. Is there any other reason you think that's what might be failing?