I carry an old Acton code reader in a bag behind my back seat, and have been known to read and clear codes on the run while commuting. Been there...done that. It's been years since I've had a code, though, and I attribute that to removing the oiled K&N filter. My codes were O2 sensor related, and normally didn't come back for a couple months after clearing. I had my MAF cleaned and left the K&N out.