[zolck510]

I randomly decided to connect my OBD tool (OBDLink MX+) and read some codes right at start up.

Within the first minute or so of starting the car cold on a 45 degree morning (started up just fine), cylinder 1 got two misfires. And then that was it. No more misfire reads and the PID status went to 0 and stayed there. Drove for another 5 minutes or so and the misfire count did not change at all. No CEL or code thrown in this process.

Is this just normal behavior on cold starts? Couple random benign misfires?

 

[BillG]

Yes, totally normal to get the occasional misfire (cold OR warm). For a Gen2 Sienna (12-18 years old) that's not bad at all! The threshold, from what I saw, appears to be 2%, which is something like 20 in a minute (at cold-start idle RPM) on 2 consecutive drive cycles to throw a code and something like 100 per minute to fire a flashing MIL indicating the potential for cat damage.