Got a '02 Honda Civic LX sedan with a D17A1 engine on 5/14/18.
The car is in LIKE-NEW condition, but with a (6/23) odometer reading of 184,843 miles. The car ran great for a while, then the engine started overheating. I then noticed an overfilled coolant reservoir with a small stream of bubbles in the coolant. I assumed this was caused by exhaust gas leakage through a blown head gasket (like my last Civic, a '99). I replaced the head gasket with an aftermarket (MLS) part from Evergreen Parts on Amazon.com (NEVER AGAIN!). I inspected the head surface for excess warpage. A 0.002" feeler gauge was a go in some places, a 0.003" gage was a no-go. I thought this was within the 0.002" service limit. I put the engine all back together with a new timing belt, tensioner, valve stem seals, (OEM) thermostat & synthetic oil. The engine ran great for a while but now the exact same symptoms are back. The engine is overheating with bubbles in the radiator neck. The electric fans work as they should. There is no white smoke from the exhaust. There is no evidence of coolant in the oil.

6/24/18 update - I tested for exhaust gas in the radiator filler neck and it was POSITIVE. I think this means I can stop testing. Clearly, there is a leak, my only remaining question is WHERE, (e.g. head warpage, head crack, block crack). I've ordered an OEM gasket set and I plan to have a machine shop shave the head after I pull it AGAIN. I've learned a lot from this forum and from Youtube. Do y'all think I on the right track? Any advice for me?

6/30/18 update - I pulled the head again, cleaned the mating surface & got a 0.003" feeler gauge under a Blue Point machinists straight edge in some places. This time I saw obvious breaches between the combustion chambers and the coolant passages. DUHHH... I brought the head to a machine shop in Vegas. For $45 the owner "Israel" hot dipped the head and shaved off 0.006" on a milling machine while I waited (about 30 mins). :-) Vegas is all about SERVICE! :-) I could not get a 0.0015" feeler gauge under the straight edge now! :-) I will update after installation & test drive. Stay tuned! :-)

In the cylinder head pic, the top pic is before shaving, bottom pic is after shaving 0.006"

7/2/18 update - I don't think that this combustion gas leakage problem was caused by a failed head gasket. I think that the leakage was caused by head warpage that was caused by overheating. I recently noticed clear evidence of this when I took a closer look at the two gaskets. In the head gasket pic, the top head gasket is the new Evergreen one I installed after only 600 miles of use. The bottom head gasket is the aftermarket one that was on the car when I bought it about 7 weeks ago. There are very similar breach patterns between both gaskets that I marked in red. The aftermarket (Evergreen) gasket would have probably worked fine if I had just shaved the head before using it. I STILL lean toward using OEM parts exclusively on Honda motor vehicles (cars & motorcycles). A personal preference of mine. I don't like to compromise proven high quality. :-)

7/9/18 update - I finished the install and completed several test drives. This engine is FIXED! It runs like a sewing machine once again! No more coolant loss or overheating. Flawless performance in city and highway driving with a nice SMOOTH idle. In conclusion, I think that many "blown head gaskets" are improperly diagnosed. The actual cause is CYLINDER HEAD WARPAGE from overheating. Honda is dead serious about the 0.002" service limit for head & block surface flatness. Live and learn. Happy motoring! :-)