Stumbled across the same issue with my '04 Avalon and an 'el cheapo eBay ELM327 clone ( $10ish ). Appears to have initial comms error as it operates on a slower BAUD rate on these pre-'05 / '06 cars. Interestingly ELMScan Toyota (available as a free demo on Android Play Store) seemed to not take issue at all and worked seamlessly, even does freeze-frame data for any DTC's thrown.