Rough Idle/Gas Smell/CEL Codes

[Jake Oleszak]

It's just an OBD2 Bluetooth device. I picked up a cheap $20 option off of Amazon. The refresh rate isn't great but it was cheap. The best one on the market is OBDLink MX, it runs about $70.

I found a bunch of useful info on how to use the app from the F150 forums. It's the same engine, just different accessory configurations. I looked on f150forum.com.

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I looked on the f150forum for some insight on my issues (I don’t know why I didn’t think of that sooner). Everywhere I look is saying stuck open injector, bad VCT solenoid, or clogged cat. Jeeeesus.

What to do what to do.....


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[Jake Oleszak]

Update: I went back to the dealer today to have them reset the KAM memory (they were under the impression that this is an absolute must and can only be done at a dealership and removing the negative battery was not sufficient). They also rescanned the vehicle and noticed a misfire still exists in cylinder 2, though no codes were being thrown. The scan showed the misfire only at RPMs lower than 1,500 and the chart would level out and appear normal above 1,500.

So I got home and decided to replace the spark plug and coil. The plug I originally bought was NOT Motorcraft for whatever reason (the plug I used needed a 5/8 socket vice a 9/16 for Motorcraft and I think did not fit the spark plug well properly, causing fuel to seep out). The new coil is now Motorcraft as well.

So new plug and coil, I removed negative terminal for 15 minutes to reset codes, then took it for a 25-ish minute drive (about 10 miles or so). The rough idle is still there at low RPMs in driving gears but goes away at high RPMs. The truck still hesitates when accelerating from a stop and is even worse in reverse.

When I got back from my drive, I decided to peep the catalytic converters. The drivers side looked fine, but the passenger side was glowing inside.

Could this be it?! The symptoms are all there: long crank before starting, rough idle, etc. one way or another, the cat needs to be replaced, but is there any test I can run before paying to get that done to ensure I won’t be replacing another cat weeks later due to the same misfiring issue?!?!


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[Adieu]

I'd just replace the injector. It's not worth the hassle of removing, trying to clean or even paying someone. New stock OEM's can be had for $35ea.

The hard part is getting fuel out of the rail and not making a mess. It's a return less system so the rail always has fuel and most times it's at 30psi.

I think there's a connection in the passenger footwell that you can pull to kill power to the fuel pump while it's running. The truck will die around 20psi. The problem still exists that you have 20psi in the system.

I ended up getting a yogurt cup to put under the injector to catch most of the fuel. That and a bunch of rags so the fuel doesnt seep into the spark well and cause a misFIRE.

Remove the PCV lines and all of the electrical connectors. Doing bank 1 might be tougher, you may need to remove the ECU to really get in there, but if you're only changing #2 you may be okay.

There are 2 8mm (I think) bolts on each side holding the rail to the manifold. Remove the 2 on bank 1, leave the other side alone. Use compressed air to get all the dirt off the top of the engine. Spritz some WD or other lube at the point the injectors go into the manifold. Gently pry up on the entire rail for bank 1 and all 4 injectors will come out with the rail. Remove the metal retaining clip and pull the injector out. Fuel will go everywhere. Lube the new orings on the new injector and pop it on. Pop injectors with the metal clip in place, it should click. Now for the fun part. You need to remove all the lower orings for the other injectors and replace or you will probably get a new misfire. Or just replace all 4 injectors for piece of mind. Make sure the manifold holes are clean and lubed and reinstall.

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Eh why???

Is this a 2nd gen thing?

I swapped a faulty injector on my '09 in like 5 minutes, just pulled up the fuel rail, clicked it out, spilled the usual teaspoon or two of gas, clicked in the new one, bolted the rail back up and that was that...

Probably put a drop of oil on the oring, I forget, but definitely didn't do anything else

Plenty of miles since, no more misfires

 

[John Stephan]

Your cat is glowing because raw fuel is dumping into the exhaust. The catalyst is there to burn off the unburnt fuel and when its raw fuel it gets extremely hot. When this happens the catalyst melts into a blob and clogs the exhaust.

You could also have a bad ECU driver. Using the crank signal the ecu grounds the necessary wires to the coil or to the injector to control timing. You could have a broken wire or you could have a bad ecu.

2 wires going to each coil or injector. One is always 12v hot. The other is the command signal for ground. You can buy a noid light set and just plug the light that fits into the harness connector and see if the circuit is working. Or you can trace the wires back to the ecu and check for continuity.


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[Jake Oleszak]

Your cat is glowing because raw fuel is dumping into the exhaust. The catalyst is there to burn off the unburnt fuel and when its raw fuel it gets extremely hot. When this happens the catalyst melts into a blob and clogs the exhaust.

You could also have a bad ECU driver. Using the crank signal the ecu grounds the necessary wires to the coil or to the injector to control timing. You could have a broken wire or you could have a bad ecu.

2 wires going to each coil or injector. One is always 12v hot. The other is the command signal for ground. You can buy a noid light set and just plug the light that fits into the harness connector and see if the circuit is working. Or you can trace the wires back to the ecu and check for continuity.


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My initial thought was faulty injector, but the tech at the dealership read the fuel trims and said nothing was off about them. I didn’t get to see the charts, but I don’t think he would have held that back from me.

I’m sure that was the reasoning for the misfire, causing fuel to be dumped into the cat and now that cat is just toast. Could that bad cat be the sole cause of the vehicle running rough and long start??


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[John Stephan]

A glowing hot cat is always raw fuel. If the O2 is functioning properly that wouldn't happen. If the fuel trims were normal, that wouldn't happen. The O2 sets the fuel trim. Short term and Long Term. If fuel trims are so out of whack, the vehicle will stay in an open loop status and never rely on data from the O2.

A failing fuel pump driver will cause poor running and long crank times, but not a raw fuel or glowing hot cat.



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[Jake Oleszak]

A glowing hot cat is always raw fuel. If the O2 is functioning properly that wouldn't happen. If the fuel trims were normal, that wouldn't happen. The O2 sets the fuel trim. Short term and Long Term. If fuel trims are so out of whack, the vehicle will stay in an open loop status and never rely on data from the O2.

A failing fuel pump driver will cause poor running and long crank times, but not a raw fuel or glowing hot cat.



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The fuel trims were not out of whack at all. They all read normal according to the dealership. The only thing they found to be strange was the cylinder 2 misfire at low RPMs, which I figured was caused by the plug not seating properly. Since I switched to Motorcraft, the "misfire" conditions still exist, but there is no longer a raw fuel smell around the vehicle. But now I've noticed the cat glowing last night after testing.

This is how I'm understanding it: The B1S1 O2 sensor was reading rich conditions caused by the cylinder 2 plug that was not in the head properly (because I mistakenly used a non-Motorcraft plug). The malfunctioning plug did not burn all the fuel in the cylinder and being pushed out in the exhaust. The O2 sensor detected this, popped the code, and the fuel clogged up the cat.

I thought a plugged cat would 100% cause rough idles, hard starting, and hesitation on acceleration.

And on another note... I've now noticed rust holes in my muffler making the exhaust sound like total crap lol.

 

[John Stephan]

Yes a clogged cat will cause a richcnditio as well because of too much back pressure. Typically misfires will happen on cylinder 1&5. They have to push gasses the farthest and the back pressure plus other cylinders trying to do the same will back up. Your O2 is pry fine but your cat may be clogged. Bang on it with a mallet and see if it rattles.

If the voltage on the rear O2 matches the voltage of the front as it cycles, the cat is bad. Rear O2 signals will be constant .8 volts at idle typically.

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[SEPTIC PROFESSOR]

Here's the stark reality: Only own an 03 or an 04 5.4, everything after those years is junk.
Go out and find a rust free 03 or 04 5.4 that runs nice for a few thousand dollars and stop
wasting your time and money on junk.