D.j. LaBombard Jr.

Can a dirty maf throw a misfire code in one cylinder?

F150Torqued

Probably NOT. Most likely need to replace plug / boot and clean / stretch spring and make sure there is no moisture or greasy finger prints on anything to compromise high voltage electrical integrity.

D.j. LaBombard Jr.

New plug, threw a code, replaced coil, ran fine for 2 weeks. Then threw a misfire code in the same cylinder and lean code in banks 1 and 2

F150Torqued

Biggest part of all misfires can be eliminated this way. Boots can look fine but have small cracks from 100s of heat / cool cycles that harbor moisture and provide arc over path for the high voltage ignition. Spark plugs CAN be defective out of the box or cracked internally - or on installation. Or that 'green' oxidation on the spring or coil tip that acts as a resistor.

The lean codes are not normal or good and need to be eliminated. But it is super unlikely that they are causing the misfire. Actually misfires will CAUSE lean codes, but more data is needed before determining that since both banks are lean (and you report misfire only one cyl). First order of business on that is to make double dog sure you have absolutely NO vacuum leaks and clean the MAF.

D.j. LaBombard Jr.

I'm gonna clean the maf since i doubt it's ever been, I'm gonna check the new coil and then swap with another to see if the problem moves

D.j. LaBombard Jr.

Update..... Swapped coils 1 and 3, made sure boots were clean. Sprayed maf cleaner on the sensor even though it didn't look dirty. Fired up and still had a miss. This morning it died while idling and CEL came on. Just got it scanned. Only maf sensor code came up, no misfire or lean code

techrep

iTrader: (1)

F150Torqued

Not trying to be a smart-*** here, but it is certainly more helpful to have the actual code numbers rather than a diagnosis description formed by the one asking for the help in the first place.

The MAF has the intake air temperature sensor inside the same sensor - so before replacing the MAF (which could possibly be indicated as @Techrep notes), It could also be as simple as a bad connection caused during the cleaning procedure - depending on which code it is.

Which One of these?


P0100 Mass Air Flow Circuit Malfunction
P0101 Mass Air Flow Circuit Range/Performance Problem
P0102 MAF Circuit Low Input
P0103 MAF Circuit High Input
P0104 MAF Circuit Intermittent
P0105 MAP/BP Circuit Malfunction
P0106 MAP/BP Sensor Range/Performance Problem
P0107 MAP/BP Sensor Low Input
P0108 MAP/BP Sensor High Input
P0109 MAP/BP Circuit Intermittent
P0110 IAT Circuit Malfunction
P0111 IAT Circuit Range/Performance Problem
P0112 IAT Circuit Low Input
P0113 IAT Circuit High Input
P0114 IAT Circuit Intermittent

And, based on these developments, I should ask how are you determining the misfire issue? Is it a P0303 - or a P0353, or just feel?