There is no more challenging failure than an intermittent failure.
Sometimes, throubleshooting the problem means installing an exhaust hose on the tailpipe (carbon monoxide kills) and warming the engine until the problem returns. Sometimes, it's a test drive.
There is some anecdotal evidence about coil failures on the Gen 2 camry, but you can't count on that right now. Just run the diags from the manuals and see what results you get after you re-create the failure.
Sometimes, throubleshooting the problem means installing an exhaust hose on the tailpipe (carbon monoxide kills) and warming the engine until the problem returns. Sometimes, it's a test drive.
There is some anecdotal evidence about coil failures on the Gen 2 camry, but you can't count on that right now. Just run the diags from the manuals and see what results you get after you re-create the failure.