2001 Explorer Sport 4.0 SOHC Cylinder Misfire Codes | Page 2 | Ford Explorer Forums - Serious Explorations

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2001 Explorer Sport 4.0 SOHC Cylinder Misfire Codes

Intake configuration

From the data it appears that bank 1 is running rich and causing misfires on that bank. It's interesting that only the rear two cylinders are misfiring and not the forward cylinder. As I recall the 2001 has some similarities with the Sport Trac and differences with the earlier Sport. Before going any further I'd like to confirm the configuration of the intake system. Please compare the photos of my 2000 below with your intake system and post any differences. Also, is your intake system completely stock?

Lower intake manifold (bottom):
LWRBOT.JPG


Lower intake manifold (top):
LWRFRT.JPG


Upper intake manifold (bottom):
UPRBTM.JPG


Upper intake manifold (top):
UPRTOP.JPG
 



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I have simular problems with my explorer XLT, ive changed the plugs, changed the oil and the fuel filter and used a gas treatment ive asked the same question to a proffesional and they told me i could have a intake leak, ive worked on M1 tanks in the army but i tell ya this truck have got me confused. The misfire and bad idele still exsist and im looking at takeing it to someone who is a little more savey than i, ive been hopeing its somthing as simple as a bad sensor being that the check engine light is on.

Any suggestions?
 






Not a match for your intake

The upper intake manifold in my early production 01 Explorer Sport is a two-piece design split into 2 halves that are bolted together, upper and lower. It is more rectangular, and angles the throttle body toward the passenger side headlight. I changed all the silicone seals on the upper and lower except the big one that seals the upper and lower halves of the upper IM. I will check it for vacuum leaks with propane or carb cleaner tomorrow.
 






How many miles are on the HO2 sensors?
 






I would say either cat converter problem or cam timing is off. Usually when the cam timing is off you will get rich on one side and lean on opposite. All this bearing in mind that you have ignition sysytem up to snuff.
 






Only one cat

I would say either cat converter problem or cam timing is off. Usually when the cam timing is off you will get rich on one side and lean on opposite. All this bearing in mind that you have ignition sysytem up to snuff.

I also considered a blocked cat but in ironhed85's case there is only one cat. I agree that cam timing is a possibility. In the original post misfires and rich conditions were occurring on bank 2 (5, 6 and sometimes 4). There's no mention of a lean condition on bank 1. After all of the chains were replaced the misfires/rich are on bank 1 and the lean condition is on bank 2.

Edit: Post 7 states bank 1 is lean.

ironhed85, did you use the special timing tool set when you timed the camshafts? The crankshaft holder in the tool set is rather flimsy. Are you sure the camshaft timing is correct?
 


















2001 early producion explorer sport

Streetrod, the intake manifold that you have pictured is what is sitting atop my engine. It sounds like there are doubts to whether this is the correct motor for this year vehicle; please voice your thoughts.

I used the OTC cam alignment tool to stabilize the valvetrain, but understand that the driver's side chain guide was obliterated before I locked down the cams. Now, there is nothing that says the cams are timed perfectly, however there were some indications from the camshaft geometry that suggested they were set up correctly. I believe the rectangular section used to lock down the cams were supposed to be parallel with the edge of the cylinder head. It does not mean that the camshft is without design flaw or that this is correct. In retrospect, I should have used a degree wheel and dial indicator. Since I did not have cam specs, or a factory service manual, I took the easy way out.

Let's consider though, 1'st: the vehicle starts and runs, very well at times. It idles good, and it has decent midrange until something in the fuel map or ignition changes. Once the ignition is shut off, and a code is allowed to set, the drivability turns to ****. This engine does, like I said, run like a raped ape at WOT under all conditions. It is this bouncing between good and bad driveability that has had me considering the coil pack from day one, butit could also be the fuel injection changing fuel trims or the engine being outside the limits of fuel trim.

I guess the questions would be:

1) Is this the original engine with 108,000 mi. or a scrapyard replacement with different volumetric efficiency?

2) Is the cam timing correct, what is a quick and easy way to eliminate this as a problem without significant disassembly of the engine

3) Where do I stand with my O2 sensors? I will add a post script about that issue.

4) Where do find a V8 donor vehicle so that I can throw this engine under a bus!


P.S. The O2 sensors on the Y pipe as well as the sensor rear of the front cat are aftermarket. The two front sensors are newish but not a manufacturer that I recognized. None of the sensors have alignment tabs to fit the factory connectors. When I first put the engine wiring harness back on the tranny, the connectors were (I believe) reversed between the passenger side (B1S1) and the rear (B1S2) because the O2 voltage dropped down to zero after the front cat heated up on B1S1. Now B1S1 AND B2S1 are reading voltage when running the engine. I needed to fabricate an extension harness to get from the grey O2 sensor connector to the passenger side O2 sensor. The location to connect the O2 sensor was between the tranny and the body and it was a ***** to get at. With the extension harness I disconect the O2 sensor in a much better place.
 






2002 intake manifold

The eBay intake manifold photo I posted supposedly is a Ford Explorer 4.0 SOHC V6, PN 1L5E9K479AH. I checked the Ford PN against the data base and it is not currently valid. I know the manifold is a 2002 because one of the photos has a date stamp as shown below.

Intake2002.jpg

The date is 2.20.2002
If you use a mirror you may be able to read the PN and date on the rear of your manifold. I suppose there is a possibility the engine has been replaced. If so, I wonder if the PCM was reprogrammed. Although, there may have been no need to. I think the only significant differences in any of the SOHC V6s is the variable induction system and the return fuel system on the 97 and 98.
 






Intake manifold design

I took pictures of the intake manifold last night but found out that I am restricted from sending attachments on this site. However, the part number from the rear of my manifold follows:

1L5E-9K479-AE
09.07 2000 (A)
 






cats & O2 sensors

According the MagnaFlow your passenger side down pipe and cat should look like below.
23314.jpg


And your driver side down pipe and cat should look like below.
23315.jpg


My original equipment look almost identical to the above.

If you now have a "Y" downpipe feeding a single cat and muffler instead of an original dual cat/down pipe I wonder if the PCM is confused. Switching around the O2 sensors before and after the engine swap could explain the change in the banks switching from lean to rich and visa-versa. When at WOT the PCM goes open loop, utilizes stored data parameters to control the mixture and ignores the O2 sensors. Your scanner should allow you to determine if the PCM is utilizing the appropriate O2 sensors for fuel trims (pre-cat) and if the O2 sensors are working correctly (voltage varies from 0.2 to 0.8).

I'm getting ready to go out and finish installing my transmission valve body, filter and pan. Later today I'll check my wiring diagrams to see what the colors are for the various O2 sensors. They should be the same for your 2001. Then you can check to see if your wiring allows the PCM access to the correct pre-cat sensors. The post cat sensors are mainly used to check the cat efficiency but over time can have an influence on the fuel trims. Your problems may have nothing to do with camshaft timing, ignition, fuel injection or compression. It could all be due to a non-standard exhaust with non-functional O2 sensor capabililty.
 






O2 wiring

HO2S #11 (Bank 1 Pre-cat)
Gray/Light Blue (O2 voltage to PCM)
Orange (sensor return common)
Red/White (Heater output to PCM)
Light Blue/Orange (heater supply)

HO2S #21 (Bank 2 Pre-cat)
Red/Black (O2 voltage to PCM)
Orange (sensor return common)
Yellow/Light Blue (Heater output to PCM)
Light Blue/Orange (heater supply)

HO2S #12 (Bank 1 Post-cat)
Red/Light Green (O2 voltage to PCM)
Orange (sensor return common)
White/Black (Heater output to PCM)
Light Blue/Orange (heater supply)

HO2S #22 (Bank 2 Post-cat)
Purple/Light Green (O2 voltage to PCM)
Orange (sensor return common)
Tan/Yellow (Heater output to PCM)
Light Blue/Orange (heater supply)

If your PCM were set up for four O2 sensors instead of three you should be getting an O2 heater related DTC.

The PCM cycles the fuel mixture between lean and rich looking for a voltage swing output from the O2 sensors. Your DTCs (P1132 & P1151) indicate unsuccessful cycling on both banks.
 






What are the numbers on your PCM? I am not 100% positive but close to it that you should not have that intake on your 2001 Sport. What is your production date?
 






Engine VIN location

The tenth digit of the 17 digit VIN indicates the year of manufacture. The identifier changed in 2001 [1998(W), 1999(X), 2000(Y)------2001(1), 2002(2), 2003(3)]
For the SOHC V6 the last 8 digits are stamped on the rear of the block on the driver's (left) side as shown in the photo below by shelbygt. The W on this engine means it is a 1998.
vin.jpg

You may be able to see it with a mirror. I haven't tried. If you can see it then you can compare it to the full VIN to determine if the engine has been replaced.
 






Duh!!!

Let me ask you a question:

What would happen if the B1S1 O2 connector were connected to the dirver's side O2 sensor from the get go, and I was switching between the B1S2 and
B2S1 connectors. If the primary sensors for banks 1 and 2 were switched, how could this engine maintain fuel trim at all?

Is it possible for my code scanner to have the wrong output designation for the voltage info. B1S1 instead of B2S1? When I re-installed the engine wiring harness, the driver's side O2 connector looked idiot proof in its location, I will have to put the Sport back up on the lift and re-evaluate this.

BTW, thank you Streetrod for the helpful illustrations. I have to say that I believe the engine to be original from the date stamp on my upper IM, and the exhaust is what my parts vendor brings up for factory replacement:

Y-pipe with two pre-cats, primary cat, secondary cat, muffler, resonator. This vehicle's exhaust sounds like a scuba diver breathing out of a straw. I plan to cut everything off after the primary cat with a 2 1/2" exhaust and a 3-chamber flowmaster once I get the engine running correctly.

Since I am discussing mods, I plan also to plop in a solid front axle assembly; perhaps a Dana 44 out of an early bronco, probably coil sprung with radius arms and a panhard bar. Lift it 6" with Early Bronco coils and leafs, add 33's possibly selectable lockers, and Voila a trail rig that is streeted.
 






Hi, just thought I'd throw some input in here. I had some similar problems, running lean, misfiring on only a few cylinders, misfires changing cylinders etc. What I found was I had a vacuum leak, which depending on where it is on these engines can cause different things to happen.

I had an intake leak just before the TB, which caused a bank 2 lean, and cylinder 5 and 6 misfire. Why it didnt cause a random misfire, im not sure.

Anyways, check for a vacuum leak if you haven't already, I didn't read through all the posts.

Just my $0.02
 






OHV exhaust system

Let me ask you a question:

What would happen if the B1S1 O2 connector were connected to the dirver's side O2 sensor from the get go, and I was switching between the B1S2 and
B2S1 connectors. If the primary sensors for banks 1 and 2 were switched, how could this engine maintain fuel trim at all?

Is it possible for my code scanner to have the wrong output designation for the voltage info. B1S1 instead of B2S1? When I re-installed the engine wiring harness, the driver's side O2 connector looked idiot proof in its location, I will have to put the Sport back up on the lift and re-evaluate this.

I doubt that your scanner is the problem. However, your wiring is suspect. It is easy to check by just disconnecting the driver side pre-cat O2 (B2S1) connector and see what DTCs get set. They should be P0150 and P0155. Then check the passenger side pre-cat sensor to make sure it's not connected as the post cat sensor.

I have to say that I believe the engine to be original from the date stamp on my upper IM, and the exhaust is what my parts vendor brings up for factory replacement:

Y-pipe with two pre-cats, primary cat, secondary cat, muffler, resonator. . .

Your exhaust system is very similar to what was used on the OHV engines. I wonder if it is the same as the Sport Trac.
 






Time to close this thread

Well gentlemen, I have found the error of my ways, it is lack of attention to detail.

I Had a 2001 Explorer Sport with 106,000 miles that was not well cared for as it was previously a leased vehicle, owned by some ****** smoker ----- cough...cough.

As a result of not keeping up with fluid servicing, the oil viscosity was frequently low and the primary chain tensioners were not doing their jobs as they were under-engineered to begin with. As you would expect, the driver's side cam chain was slack and slapping the krap out of its guide until the nylon was obliterated and the chain was on metal.

The misfire codes leading up to this problem were probably due to cam timing, and the myriad of problems that result such as cam position sensor misalignment, valve timing events too early or late, noise being picked up by a knock sensor if the vehicle even has one.

Well, I purchased the OTC cam timing kit, and a cheap offshore manufactured timing chan set which was suprisingly compreshensive although questionable on longevity. All in all I spent about 600 bucks with the felpro gaskets that I purchased for the timing cover, valve covers, intake manifolds, and oil pans. That covered tool kit, gaskets, and timing set.

It was not an easy job pulling the motor, but not the first sohc engine swap I have done. Since I am now adept at this valvetrain service, I should concentrate on making some money with it.

Anyway, when the engine started up with misfire, and rich/lean codes, I was quite dismayed, and rather frustrated. I know it is a lot of suspense listening to all of my bullshit but it is worth to find out where I went wrong in the re-assembly.

I did not think from the start that I had cam timing issues, like I said, it ran like a raped ape at WOT so it was doubtful I had serious issues with cam timing. The problem was theO2 sensor connectors for B1S1 and B2S2. They were backwards. I had the B1S1 connector on the driver's side. I was switching back and forth the connectors for B2S1 and B1S2 on the passenger side. Imagine the confusion of a closed loop system feeding fuel to the wrong bank --X-- and getting input from the wrong bank.

Oops.

Oh well, next time the system is not idiot proof, I will connect one sensor connector at at time and read the scanner to determine if it is the correct location for that O2 sensor. Since the front two O2 sensors on my vehicle have been changed out to a generic sensor with no matching alignment tabs for each connector it was not idiot proof. The entire harness that is connected to the sensors was by itself on my garage floor at one point. It is much easire for Ford to install the harness on the engine/trans without the body on the frame, but not so easy to reinstall the harness during an engins swap. I will know better next time. Last time was easier.

Thanks very much for eneryone's input, it was appreciated even though I was an ####### at times. I will endovour to do better, and perhaps give back some technical experience to this site eventually.

Ironhed85
 



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correction The problem was between the O2 sensor connectors B1S1 and B2S1, ie. the fron two sensors were crossed. Even writing about this is confusing.
 






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