P0442 causing P0300? | Ford Explorer - Ford Ranger Forums - Serious Explorations

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P0442 causing P0300?


Elite Explorer
September 27, 2002
Reaction score
City, State
Anchorage, Alaska
Year, Model & Trim Level
'97 Explorer XLT AWD 5.0L
On my drive back home from hangin with the fam, CEL decided to come on.
No rough idle or any drivability concerns.
Get home and hook up the scanner, get P0442, P0300, and of course P1000.

Did some reading on P0442, being the EVAP small leak, I can't tell if something in that system could also cause a P0300.

I'm not sure the gas cap would fit, as for one, last time I filled up was at least 4 days ago which was about 90 miles. Although I imagine still possible, I wouldn't think that could cause a misfire?

Since I know that one code can cause additional codes, I'm not sure if I should be looking at 2 separate issues, or the EVAP leak can also cause multiple/random misfires.

I just changed plugs and plug wires about 400'ish miles ago, with Autolite double platinum gapped to about .054