Misfire with P0303 and P0200 ('03 4.6L)
01-14-2019, 07:12 PM
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Misfire with P0303 and P0200 ('03 4.6L)
So, my truck started throwing a P0303 recently. No big deal, right? Just a coil pack, done them a million time. I hadn't had a chance yet to climb in and pull it, and I noticed today that I threw a P0200. That one is a little more curious. I'm not seeing much information on P0200s with F150s. I know, of course, this is a "generic" injector circuit issue. But it feels like it's not necessarily weird to see these together.
My suspicion is that this probably means I have a bad injector on cylinder 3, right? The only reason I hesitate is because I'm wondering why it threw a 200 instead of a more specific 203 to match the cylinder misfire. If the whole injector circuit was bad, it'd kill a lot more than just one cylinder, right? I have a brand new set of coil packs sitting here that were gonna go on, but now I'm second guessing myself about needing some injectors instead. Would the main test be to pull the cylinder 3 injector and check the resistance across it? Is that good enough to tell the whole story?
My suspicion is that this probably means I have a bad injector on cylinder 3, right? The only reason I hesitate is because I'm wondering why it threw a 200 instead of a more specific 203 to match the cylinder misfire. If the whole injector circuit was bad, it'd kill a lot more than just one cylinder, right? I have a brand new set of coil packs sitting here that were gonna go on, but now I'm second guessing myself about needing some injectors instead. Would the main test be to pull the cylinder 3 injector and check the resistance across it? Is that good enough to tell the whole story?
01-15-2019, 12:22 PM
#2
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i'm not finding much on p0200 for a ford either. here is the overall view of it.
https://www.autocodes.com/p0200.html
definitely check the injector.
https://www.autocodes.com/p0200.html
definitely check the injector.
01-15-2019, 12:39 PM
#3
Mark
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Just swap #3 Coil with another cyclinder ... clear codes and run it. see if the code follows the coil pack. May be a plug too.
01-18-2019, 03:49 PM
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Update: Well, I'm not entirely convinced there was a genuine problem with the injectors. I went ahead and grabbed both injectors and coil packs since they're fairly cheap anyway. I swapped all the first bank injectors out since they're easy, and measured them afterwards, only to find all four were reading right about 16 ohms. Ran the truck down the road and back, and it was smoother, but it still had a little shake, and it picked up a misfire right after clearing codes.
So I went ahead and swapped the cylinder 3 coil pack after that, and boom, truck purrs away. The second I cranked it I could tell the immediate change. Cleared codes, nothing came back. I'm thinking that maybe the pack died, and with that cylinder not firing, maybe it just fouled the injector on it. Pretty much speculation, but it sounds reasonable saying the words together that way, so I'm gonna run with that explanation.
So I went ahead and swapped the cylinder 3 coil pack after that, and boom, truck purrs away. The second I cranked it I could tell the immediate change. Cleared codes, nothing came back. I'm thinking that maybe the pack died, and with that cylinder not firing, maybe it just fouled the injector on it. Pretty much speculation, but it sounds reasonable saying the words together that way, so I'm gonna run with that explanation.
