I almost always disconnect the battery like stated to get a second opinion. Works for humans too. Lol. The computer isnt perfect either. Sometimes its just a spurt signal that may mean nothing. 93,000 miles on VX no light, 98 Trooper used to get weird O2 sensor garbage, second opinion would turn it off, and it wouldnt return for 4 months or so. Weird. If something is wrong, youll know by the quick check engine light returning.