amusement

Learned a lesson in trouble shooting today.

If a 2001, or about, 4runner has random cylinder misfire (P0300) and number 3 cylinder misfire (P0303) codes, plus VSC OFF, VSC TRAC and ENGINE lights are on the problem, my friend, is not a mechanical one.

Vehicle sounded real good when scanner reported the codes. No misfire could be detected.

Just in case I swapped #3 coil with #2 coil and nothing changed.

Reset codes and all was well..until

Checked the battery and it was 3 months over it's expiration date with a heap of corrosion hidden under the red battery boot. A little battery terminal cleaner and silicon di-electric grease and all was well.

Possible low voltage caused the erroneous errors.

In a couple of days the 4runner will get a new battery and the fix, hopefully, will be done.

amusement

Battery replaced still misfire when engine is warm at or about 50mph, no codes.

Let up throttle and misfire goes away.