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Serious issues at 340k


Rochev96

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I bought my father in law's 2002 V6 he bought new. It has been driven with the OD/OFF light flashing and engine light on for "years". It's misfiring badly and can't usually get out of its own way. The transmission shifts into OD just fine and stays locked in at around the 45mph acceleration test. My main concern right now is the engine codes for every o2 sensor. Those are the only important codes I got. I attached a photo from FORScan showing the o2 sensor results. I'm a bit confused on exactly what this means as the results are odd. It says the voltages are normal and the only misfire detected is a slight non catalyst damaging one... Should I go ahead and replace the upstream o2's? And would that alone be causing the severe misfiring? I'm hoping the cats aren't toast.
 

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plasticseng

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I bought my father in law's 2002 V6 he bought new. It has been driven with the OD/OFF light flashing and engine light on for "years". It's misfiring badly and can't usually get out of its own way. The transmission shifts into OD just fine and stays locked in at around the 45mph acceleration test. My main concern right now is the engine codes for every o2 sensor. Those are the only important codes I got. I attached a photo from FORScan showing the o2 sensor results. I'm a bit confused on exactly what this means as the results are odd. It says the voltages are normal and the only misfire detected is a slight non catalyst damaging one... Should I go ahead and replace the upstream o2's? And would that alone be causing the severe misfiring? I'm hoping the cats aren't toast.
With O2 sensors, it is much more useful to graph the outputs from the sensors, since they are continuously changing. Forscan will do that for you. You are looking for a constant switching on the upstreams (almost like a sinewave), and a more consistent value on the downstream sensors (if the cats are working correctly).

If you can post up the graphs, a lot of people here can help.
 




Rochev96

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Thank you for that info. I checked the plugs and there's literally NO electrode left at all. I can't believe it was even driving. I'm replacing them and if it doesn't fix it completely, I'll report back with those graphs.
 




Rochev96

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New plugs helped acceleration but it still won't go uphill and makes no power under 2800rpm. Even flooring it heading uphill does nothing. Engine still shaking a sputtering at idle, has stalled putting in reverse.

OD OFF still flashing. Engine light hasn't come back on in 100 miles. I have a genuine elm327 and forscan that I used before to tweak a transmission in an Escape, but I don't see any transmission section at all. I know you can find them on forscan but mine doesn't show anything for transmission anywhere like last time. Does anyone know more about that? I need to know if it's something serious like failing converter or clutch. It's completely rotted out, even up to the rear windows so it's definitely not worth doing much to.
EDIT: The only codes are for random misfires and pending for p0174 (too much air in exhaust)
My o2 graphs looked ok, o2 1-2 though, would oscillate very small amounts and steadily climb while o2 1-1 was very clearly oscillating and staying in the middle.
 
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Mbrooks420

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Did you do wires? I’d assume given it’s terrible history every single tune up item and fluid is due.
 




Rochev

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Did you do wires? I’d assume given it’s terrible history every single tune up item and fluid is due.
I actually just started thinking of that. I'm trying not to throw parts at it but at $40 it's reasonable. I ran a thorough live data test on forscan and fuel injectors, air, evap, etc all were normal. I did get p0741 even though the trans is shifting ok. Shifts in/out of OD as should and I can still control it with the button. Will have to check the fluid level, it seems low as it sometimes takes a few seconds for R or D to engage.
 




Mbrooks420

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The shift delay is likely servo bore wear
 




Rochev

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I forgot to mention-
I have p0174 (bank 2 lean) and a few multiple and random misfires. The plugs on bank 1 were very worn, but the plugs on bank 2 (lean bank) were absolutely gone, zero electrodes. They were normal, no fouling etc.
If cylinder 4-5-6 or any combination of them were misfiring, would it still say "random misfire" or would it narrow it down to which one(s)? I'm wondering if just bank 2 is misfiring.

I did verify the maf, iacv, brake booster and pcv are functioning as it ran worse or stalled when removed. No abnormal exhaust smoke or smell. Couldn't find air leaks by spraying everything. I'll be replacing the plug wires but I'm not too confident it'll fix it. Smoke tester is next. Since it's not telling me what cylinders are misfiring, I'm assuming it's a vacuum leak or something affecting "random" cylinders but the bad plugs on bank 2 are throwing me off.
 
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Mbrooks420

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Wasted spark. It’s normal for the one bank to be much more worn.
 




Rochev

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Wasted spark. It’s normal for the one bank to be much more worn.
Thank you, I appreciate your input. If ignition wires+coil pack don't help I'll do a smoke test.
 
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Rochev

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So- New plugs, wires, pcv, filters, maf clean, tb clean. No change. I unplugged the front o2 on bank 2 and it stalled. Here's the graphs of the front and rear o2. The dip in the green and blue (rear) is from revving it up a bit. Any knowledge and advice is GREATLY appreciated. It seems the green (o2 1 bank 2) is dead? I unplugged it but it didn't make a difference, hoping it's because it's not working anyways. I'm stopping here before I replace the coil pack and clean the egr, in case that o2 is an issue. It did have an active code for that o2's heater circuit.

o2 graph.PNG


o2 rear.PNG
 
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DFOFF

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What do your long term fuel trims look like? It hard to make a call on short term without knowing where the long term is at.
 




Rochev

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Here they are at idle, after it settled down.
3rd pic is driving around 50mph.
MAF voltage was right around 6.4v at idle.

ltft.PNG


ltft table.PNG


ltft drive2.PNG
 




DFOFF

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I would say you have a vacuum leak somewhere that is only effecting bank 2. It is not so big that is causing the engine to die, but your electronics are dumping a lot of extra fuel into bank 2 trying to compensate for it (by those long term fuel trim numbers it's dumping the max that it can) and if you are still getting a lean code it's still not getting enough fuel to overcome the air leak. So I would start checking anything that is going to allow air to get into just that one bank of the engine and that will probably remedy a lot of your issues. The fuel trim numbers on bank one are within reason.
 




Rochev

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Thank you DFOFF. I ordered a vacuum leak smoke tester and I'll report back when it comes in. I'm gonna wait to do that before continuing to replace things.
 




Rochev

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Smoke tested the intake system on both sides and got a lot of smoke out of the EGR valve and the intake manifold seat on cylinder 3. Would those leaks, especially cyl#3, cause the lean condition on bank 2? I'm going to take everything off and clean it up and replace all gaskets. No smoke came from anywhere else.
 




DFOFF

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Not trying to be insulting, but the cylinder that was leaking was the back cylinder on the passenger side of the vehicle. That is weird because that would be bank 1. I would also have thought that that would of given you a misfire on that cylinder. It is possible though that the egr leak (where was it leaking from? The egr body, exhaust connection or flange connecting to intake manifold?) could be causing your lean condition, but that should effect all cylinders not just bank 2. The leaks you found are definitely causing problem so it's a step in the right direction. I would certainly look that intake over good while you have it out. Put in all new seals when you put it back on.
 




Rochev

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Yeah it was cylinder 3 that smoke was coming from. I'm including a photo of the valve stem on cylinder 4, it's the only one that's not surrounded by the cylinder. It looks as if it's recessed/dropped.

Below is cyl#4 valve stem which is lower.
20201018_152809.jpg

And the rest are sealed in as normal:
20201018_152913.jpg

I'd think it would say cylinder 4 misfire and not just multiple, maybe the vacuum leak was causing chaos.
 
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Rochev

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Update:
I turned the crank a lot and the lifter did open more and close but not fully, but I stopped rotating it. Not 100% sure on that one. I replaced all intake gaskets. Smoke tested it and no smoke came from the intake anymore, but a lot came out of the holes under the EGR valve again. Only codes that came back are "random multiple misfires" and the engine did NOT want to rev above 4500rpm. Compression test hopefully tomorrow.
 
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DFOFF

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I am not very familiar with the EGR on this engine (weather it should leak during a smoke check or not). I've read a few things that say they can leak a little and still be good but not sure where from or how much. Have you checked the EGR to see if it is closing and sealing off the port to the intake, if not, I think I would, if possible, block off the flange of the EGR to the intake (also block off the vacuum lines running to the EGR, in case the diaphragm is bad and they are sucking in air or if you have a hand vacuum pump you could check the operation of the diaphragm) and then start the engine to see if it was sucking air in through the EGR.
 




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