So I recently purchased an 07 S2000 with 45000 miles (30000 miles with kit installed) and a SOS stage 2 kit, flashpro tune, upgraded heat exchanger, Comptech header, and ID1000. I was looking for a stock S2000 but this one was in great condition with all the parts and receipts installed at a Honda dealership which is also where I purchased it. The original owner traded it in. I dont have the paperwork for the tune and dyno results but it was tuned on a dyno with a 3.6 inch pulley by a reputable tuner, John Reed Racing.

Anyhow while driving some twisty roads a week later the CEL flashed for a few seconds during acceleration. It went away and the car drove just fine. However I do notice every so often during hard acceleration runs the CEL had flashed again for a second or two. Not all the the time maybe just once or twice Ive noticed this past week. The CEL has never stayed on besides the few flashes so I dont think I can pull the codes.

The idle also seems to have changed a bit. The first week I had it the idle felt normal and didnt vary. However at idle now while at a stoplight the idle will surge to 1300 RPM then drop back then to 900-1000 then surge again every 7 seconds or so. The car was tuned in Oregon and am in Hawaii now but both have 92 octane fuel and are at or close to sea level so I dont think thats the issue.


Are these two events possibly related? Is the flashing CEL caused by a misfire? I think I am going to run a compression check and also take it to a local dyno to datalog it and see if everything with the tune looks good. Hopefully the fix is something simple like changing spark plugs.