New member here...
I have a 98 Accord LX, F23A1 VTEC 4-cyl., Automatic, 4 door with 162k miles in it for the past 4 years with regular maintenance schedules. I have a couple of issues that concern me....

Car idles rough on star-up but smooths out when warm and there is oil stains all around cylinder head gap. I've checked the usual trouble spots for the idle problem and everything seems fine. As for the cylinder head gasket , there is no oil/coolant mixture and i've noticed it about a year ago....there is a slight oil loss between oil changes but never stains on driveway. I already did a at home vacuum leak test with a gauge from harbor freight and it read fine.

What kinds of test can i perform at home to find the idle culprit and if only the cylinder head gasket is bad before i take it to the shop??? And how much should i expect to pay for performed test???

I want to keep this car as long as i can but dont want to spend $1500 on replacing the gasket at a Honda dealership.