I know this was brought up recently but I had no luck searching this month's posts or the archives, so 'ere it goes. Just last night I changed the oxygen sensor because I was getting pretty bad mileage (vague but can't track cos of non functional odometer). Today I was poking around the engine bay and decided to check the oil level. When I pulled the dipstick out I was momentarily overwhelmed by gas fumes. The oil level has also risen quite a bit. I'm going to change the oil and keep an eye on it just in case the oxygen sensor isn't the fix for this. What else besides the oxygen sensor could cause this? Thanks for all. Adam.