Need help diagnosing these codes
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Need help diagnosing these codes
I have a 2002 Ford F-150 5.4 triton. The service engine soon light came on this morning. It is idling extremely rough. You can smell an odd smell coming from the engine compartment and exhaust pipe. It's sluggish when driving and I can hear almost like a clapping noise coming from the tail pipe. The codes that are present are: P0174, P0306, P0316. It's to my understanding that bank one and bank two are too lean? I'm unsure where to look for an air leak? I did replace the intake manifold gasket a few months ago. I've dumped water on it as it's running and can't hear any hissing. I'm lost on what to do or try. I really don't want to go to a shop. Any and all suggestions are welcomed.
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I would ignore P0174 until you get your cylinder 6 (P0306) misfire fixed, and that should also clear P0316. FYI, cylinder 6 is in bank 2, which is where P0174 was derived from. I'm not thinking vacuum leak because you don't have a P0171 with it, but you may have pending codes. As far as cylinder 6 misfire, Could be a plug, coil, injector.... I'd look at the injector first because of the lean code.
98 F150 5.4L E40D/4R100
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From: MI
I would ignore P0174 until you get your cylinder 6 (P0306) misfire fixed, and that should also clear P0316. FYI, cylinder 6 is in bank 2, which is where P0174 was derived from. I'm not thinking vacuum leak because you don't have a P0171 with it, but you may have pending codes. As far as cylinder 6 misfire, Could be a plug, coil, injector.... I'd look at the injector first because of the lean code.
Nick, these engines are allergic to water. Like white said, ignore everything at this point and focus on #6. Strange that #6 is going bad, did you wash the engine by chance ? Water can short a coil (COP system) quickly...whether it's running or not. If you wash the engine you have to be careful not to fill up the plug chambers. Water will sit in the chambers because there's no way for it to run off.
At least #6 is easy to work on.
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I did miss that, kind of. I assumed it was after the codes came up, but good point Brew (that would 'splain P0316). When exactly did the water come in to play?
Last edited by white89gt; Jan 27, 2017 at 11:39 PM.
98 F150 5.4L E40D/4R100
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From: MI
It was after the way I undurstood it and it makes the most sense. That's why I said there may be more DTC's in the future lol. Washing the engine or whatnot may of caused te problem to begin with since it's #6 that's bad. #6 doesn't go out as much as the the rest do , due to location. It could, but if he was dumping water....Newer heard of anyone using water to check for vac, heard of either or SF which created more leaks since it melts connection, but yet..... Best way for vac leak detection is using propane.
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I use a soapy water mixture in a spray bottle.... you'll see little bubbles if there's a leak.
However.... I've never done it on a modular motor/motor with top plugs. It's really handy on a SBF.
However.... I've never done it on a modular motor/motor with top plugs. It's really handy on a SBF.
Last edited by white89gt; Jan 28, 2017 at 10:32 AM.
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Great points guys. So I never wash my engine. This is exactly how it happened. I drove from work to the bank. Truck was fine. Then I went to Taco Bell drive through . (Maybe it got sick like I did) but as I was sitting in the drive through my truck was at a violent idol. Shaking like crazy and the rpm was dipping to almost zero then back up to 500. I left and then heard (in my opinion) sort of like a clapping noise coming from the exhaust pipe. The truck was running sluggish. Then the service engine light came on but instead of being solid it was blinking. I got home and as I got out I could smell something odd. Not fuel but a rich exhaust smell coming from the pipe and engine compartment. That's when I went to local shop and they pulled the codes I stated above. So I proceeded to go home with the same issues. That's when I got a water bottle and poked a hole in the lid so I could spray on lines, intake gasket etc... never heard hissing or visually saw anything. So at this point I'm going to try moving spark plug and coil to cylinder 5 to see if it will move the misfire. If not then what??? Also I did do the intake manifold gaskets myself but I torqued to proper specs. It was spewing coolant before. No leaks that I can see now. Hope this helped clear things up?
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98 F150 5.4L E40D/4R100
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From: MI
Things could be worse, like the use of carb cleaner. Enemy #1 to vac lines lol.
So did you charge the vac harness with , -what is it 6hg or a little compressed air, then preformed the soapy water test ? That's one way I guess, but your reversing pressure. The smoke test is good.
All that said, the mini tube vac lines rarely leak on these trucks. They become damaged when folks attempt to troubleshoot them lol. Or once they get old and shatter. They shatter like glass.
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Bubbles ? But it's vacuum, it sucks everything into lol. That's why you use a gas to check...like propane. Idle will fluctuate if there's a leak.
Things could be worse, like the use of carb cleaner. Enemy #1 to vac lines lol.
So did you charge the vac harness with , -what is it 6hg or a little compressed air, then preformed the soapy water test ? That's one way I guess, but your reversing pressure. The smoke test is good.
All that said, the mini tube vac lines rarely leak on these trucks. They become damaged when folks attempt to troubleshoot them lol. Or once they get old and shatter. They shatter like glass.
Things could be worse, like the use of carb cleaner. Enemy #1 to vac lines lol.
So did you charge the vac harness with , -what is it 6hg or a little compressed air, then preformed the soapy water test ? That's one way I guess, but your reversing pressure. The smoke test is good.
All that said, the mini tube vac lines rarely leak on these trucks. They become damaged when folks attempt to troubleshoot them lol. Or once they get old and shatter. They shatter like glass.
do do you know if a bad EGR valve can cause the P0174 & P0171 code?
98 F150 5.4L E40D/4R100
Joined: Nov 2006
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From: MI
I suppose it can, but your getting it because of the misfire. It's why we said ignore it and fix the misfire. That will disappear when the misfire does. I suggest you get on that pronto, before your cats ignite and melt shut...cuz that's next.