K&N Cold Air Intake - Check Engine Light

[jman315]

Looking for some input and help. I have a 2007 Sport Trac with the 4.6L V8 and about 78k on the odometer. Previous owner replaced the exhaust which has a good sound and decided I'd bite the bullet and buy the K&N air intake (57-2573) to compliment. After being installed a couple of weeks and a couple hundred miles the check engine light decided to turn on. As soon as that happened, the transmission also started acting jerky and shifting rough, eventually throwing the wrench light on the dash. Checked the ODB2 for codes and get P0171 and P0174. Figured with the age of the vehicle, I'd just replace the stock FoMoCo MAF sensor. Disconnected the battery and installed the Hitachi (MAF0012) brand. That worked well for about a week, and then same symptoms as before. Before I get too carried away on throwing more money and time into this thing, I thought I'd post here to see if anyone else has had a similar experience. I've been looking through all sorts of forums where people claim that the problem is an oiled filter fouling up the MAF sensor to needing a tuner or other upgrades. I'm okay with spending a bit more and doing a few other bolt on upgrades as long as it's dependable.

 

[dvdswan]

If there is too much oil on the filter it can actually fault out the MAF. Water will do the same thing and short it out.

You can get a cone filter that does not require oil on it.

 

[jman315]

If there is too much oil on the filter it can actually fault out the MAF. Water will do the same thing and short it out.

You can get a cone filter that does not require oil on it.

That was one of the first things that was mentioned. So I did buy a similar sized "dry" filter and installed that the other day, but at that point the new sensor was probably already fouled up. I tried to use some mass air flow sensor cleaner on the new MAF, but unfortunately on the short trip I made today, the CEL came back on. I'm going to go back to the OEM sensor that I also cleaned, but I'm guessing I'll see the same result. Next step will be to purchase another new MAF sensor, but cycling through a new one every week or so isn't in the mix for me.

 

[toobladink]

i had a similar issue on mine. does it make like a low hissing sound? is the intake noise pretty loud?

took a couple things for me to fix it:
one of the hose connections was loose, so i used a hose clamp where it connects. it only got loose after the car was warmed up.
there was also this threaded connection for a hose, and i had to put teflon tape on the threads and tighten it down more than what it said to (which was "hand tight").
also had to tighten the hose clamps with a socket wrench instead of a flathead screwdriver.

it's also possible that it has just exposed other parts that have worn over time. for example, your fuel filter probably isn't as efficient as it once was. maybe your O2 sensors are also starting to wear. all of these small things combined could lead to you running lean.

i don't think the oil on the filter is going to dirty up the MAF enough, especially if you didn't oil the filter yourself. that's typically only been an issue from people who oil the filter themselves and apply too much.

 

[jman315]

i had a similar issue on mine. does it make like a low hissing sound? is the intake noise pretty loud?

took a couple things for me to fix it:
one of the hose connections was loose, so i used a hose clamp where it connects. it only got loose after the car was warmed up.
there was also this threaded connection for a hose, and i had to put teflon tape on the threads and tighten it down more than what it said to (which was "hand tight").
also had to tighten the hose clamps with a socket wrench instead of a flathead screwdriver.

it's also possible that it has just exposed other parts that have worn over time. for example, your fuel filter probably isn't as efficient as it once was. maybe your O2 sensors are also starting to wear. all of these small things combined could lead to you running lean.

i don't think the oil on the filter is going to dirty up the MAF enough, especially if you didn't oil the filter yourself. that's typically only been an issue from people who oil the filter themselves and apply too much.

Thanks for the reply. I did reach out to K&N support and they suggested tightening clamps and making sure the MAF sensor and gasket was secure. I thought about using some teflon tape too on the hose barb fittings, but I was a little reluctant to remove them since they are plastic threads and seem pretty tight. I was able to tighten the clamps a bit, but even after a new sensor and a new K&N dry air filter (RU-3101HBK), I still got a check engine light after just a few trips. The new dry filter is a bit larger and actually seems to idle and accelerate smoother than compared to the oiled filter. Also, I discovered that I was able to clear the codes while I was driving and oddly enough, the check engine light hasn't come back. I also did order a Granatelli Motor Sports MAF sensor that is supposed to improve ignition and injector timing control that results in a 10 to 15 hp gain. I have yet to install that though because...

I've since taken the vehicle to a local shop and asked them to put it on a lift so I could get a better idea of what else might be in need of repair before I get too carried away on upgrades. We found that the oil pan gasket is leaking and the carrier bearing in the driveshaft is completely toast. I elected to have them replace those items and also asked them to replace the spark plugs and do a tune up. When I called them up today to see how the repairs were going, they informed me that 4 of the 8 plugs broke off in the cylinder. I've read this is a common problem with the 4.6L 3V motor. I guess I'll have to see if they are able to remove and fix it correctly or if I'll be needing to look for a new ride in the near future.

To be continued...

 

[jman315]

So after a couple weeks and a few hundred more miles on the odometer, I've still gotten the dreaded CEL. I believe though that I've been able to isolate the issue down to seeing the light when the AC is turned on. I've noticed in particular that after starting it up when the engine when it is still warm, once I put it in drive, it has a tendency to buck, hesitate, jerk until I give it a little more gas. It's actually always had this behavior since I bought it, but never had the CEL issue until after the air intake was installed. I've been able to find posts on other auto forums that mention that the ac compressor or bad iac valve can trigger a lean code and cause symptoms like this. I wasn't able to find any other similar posts about the explorer or the 4.6L in particular. Does anyone have any experience with throttle body issues with this motor? It looks like the IAC is part of the throttle body and of course it's not a super cheap part to swap.

 

[Nedwreck]

Following. I bought a 07 v8 Sport Trac, with existing K&N intake/filter setup and Gibson exhaust. I seem to be chasing the same problem. Mine did have a small vacuum leak at the EVAP gizmo, and I'm working through vacuum lines and all that. Nothing has solved it yet, so yep I'm tagging along here lol

Freeze frame data when my faults were set always seem to be around 1600rpm when it happens. Dunno if that means anything to anyone.

 

[jman315]

Following. I bought a 07 v8 Sport Trac, with existing K&N intake/filter setup and Gibson exhaust. I seem to be chasing the same problem. Mine did have a small vacuum leak at the EVAP gizmo, and I'm working through vacuum lines and all that. Nothing has solved it yet, so yep I'm tagging along here lol

Freeze frame data when my faults were set always seem to be around 1600rpm when it happens. Dunno if that means anything to anyone.

I'm leaning towards either the throttle body motor or the throttle position sensor being bad. Other threads have implied that electrical interference might be part of the problem and wrapping the wires to the connectors might make a difference. With the age of these vehicles, I've noticed that the tape and loom tubing is pretty brittle. Between the cost of replacing those two components, I think it might just be better to buy a whole new unit. Amazon sells a Hitachi replacement which is a little more affordable than the Motorcraft.

https://www.amazon.com/Hitachi-ETB0065-Injection-Throttle-Silver/dp/B09YB69DFG?tag=seriouexplor-20

 

[Nedwreck]

I'm leaning towards either the throttle body motor or the throttle position sensor being bad. Other threads have implied that electrical interference might be part of the problem and wrapping the wires to the connectors might make a difference. With the age of these vehicles, I've noticed that the tape and loom tubing is pretty brittle. Between the cost of replacing those two components, I think it might just be better to buy a whole new unit. Amazon sells a Hitachi replacement which is a little more affordable than the Motorcraft.

https://www.amazon.com/Hitachi-ETB0065-Injection-Throttle-Silver/dp/B09YB69DFG?tag=seriouexplor-20

Thank you for the link!

I don't have the stock intake parts to put back on, if you have time perhaps you could restore the stock intake bits and see if the problem goes away? Granted, that's not what either of us would want to see, but it can prove out if it's actually intake related. (If a step forward causes a problem, step it back to see if the problem goes away.. old machine maintenance trick lol)

Electrical interference... hmmmm... if these trucks are prone to that, but new devices stop the problem, that wouldn't indicate (to me) that there is actual "cross talk" or attenuation etc going on. If it's actual signaling interference (coil probs?), then foil shield looming grounded at one end would drain that.

great tips jman315, I'll be looking into these things

 

[jman315]

Thank you for the link!

I don't have the stock intake parts to put back on, if you have time perhaps you could restore the stock intake bits and see if the problem goes away? Granted, that's not what either of us would want to see, but it can prove out if it's actually intake related. (If a step forward causes a problem, step it back to see if the problem goes away.. old machine maintenance trick lol)

Electrical interference... hmmmm... if these trucks are prone to that, but new devices stop the problem, that wouldn't indicate (to me) that there is actual "cross talk" or attenuation etc going on. If it's actual signaling interference (coil probs?), then foil shield looming grounded at one end would drain that.

great tips jman315, I'll be looking into these things

I can say with 100% confidence that I did not have a single CEL with the stock intake. My issue only started after installing the K&N kit. However, even with the stock intake, I still have always experienced the same bucking/jerking/hesitation. It's particularly more noticeable though after a warm start.

Also, after running an errand earlier today, the CEL came on again even with the AC being turned off. As soon as I put it into drive and felt the surging, I just knew it was a matter of time before it showed up on the dash. Fortunately it's easy to clear the codes while driving, otherwise the trans starts throwing a fit and basically goes into limp mode until they can be cleared.

This weekend I'm going to check the connectors to the throttle body, tape them up better, use some fresh loom tubing, and put a dab of dielectric grease on the contacts to see if that makes any difference.

 

[Nedwreck]

I can say with 100% confidence that I did not have a single CEL with the stock intake. My issue only started after installing the K&N kit. However, even with the stock intake, I still have always experienced the same bucking/jerking/hesitation. It's particularly more noticeable though after a warm start.

Also, after running an errand earlier today, the CEL came on again even with the AC being turned off. As soon as I put it into drive and felt the surging, I just knew it was a matter of time before it showed up on the dash. Fortunately it's easy to clear the codes while driving, otherwise the trans starts throwing a fit and basically goes into limp mode until they can be cleared.

This weekend I'm going to check the connectors to the throttle body, tape them up better, use some fresh loom tubing, and put a dab of dielectric grease on the contacts to see if that makes any difference.

The first time I tried to reset a CEL while driving was in a 01 Taurus. The engine died lol (but restarted immediately)

I had some wonkiness with mine (low RPM lurching and some odd roughness that didn't set any misfires) that cleared up with a new fuel pump driver module. Seems like it was getting 35-39psi(?) showing in Torque, but it's solidly 40-42 while driving now. I do have some odd trans shifting things (occasional flares 1-2, 2-3) but I think that's separate. This one is 220k, no idea how well it's been serviced.

 

[jman315]

This afternoon I removed the connections from the throttle body, sprayed them with electronic cleaner and then put a touch of dielectric grease inside the pins. Both of the plugs had an inch or two of wires to the connection that was mostly exposed. So I wrapped both with some high temp cloth electrical tape and covered that with some loom tubing. I'll keep you posted, but after a half dozen short trips I didn't have any rough idling or surging. That would be silly if that's the magical fix.

 

[jman315]

This afternoon I removed the connections from the throttle body, sprayed them with electronic cleaner and then put a touch of dielectric grease inside the pins. Both of the plugs had an inch or two of wires to the connection that was mostly exposed. So I wrapped both with some high temp cloth electrical tape and covered that with some loom tubing. I'll keep you posted, but after a half dozen short trips I didn't have any rough idling or surging. That would be silly if that's the magical fix.

@Nedwreck - After another week or so of driving, the check engine light hasn't returned. Also I haven't experienced the hesitation or jerky feeling like I'd used to when shifting to D after the engine is already warm.

 

[Nedwreck]

@Nedwreck - After another week or so of driving, the check engine light hasn't returned. Also I haven't experienced the hesitation or jerky feeling like I'd used to when shifting to D after the engine is already warm.

Good deal!

After reading your previous post, I did the same things with the connections on my TB.. to no avail sadly. So I went ahead and re-inspected everything, did a smoke test (no evidence of a leak found), cleaned the MAF and all that.. still having lean codes and LTFT is over 15%... sigh

It seems like if the throttle servo doesn't act right, that the TPS would detect that and throw a code or somesuch.. but your experience isn't following that line of thought..

Thanks for the info jman!

 

[jman315]

Good deal!

After reading your previous post, I did the same things with the connections on my TB.. to no avail sadly. So I went ahead and re-inspected everything, did a smoke test (no evidence of a leak found), cleaned the MAF and all that.. still having lean codes and LTFT is over 15%... sigh

It seems like if the throttle servo doesn't act right, that the TPS would detect that and throw a code or somesuch.. but your experience isn't following that line of thought..

Thanks for the info jman!

Can you take a picture around the throttle body? I would be curious to see what the wiring leading up to the connections looks like. Below are the products that I used as well.

The cleaner I used on the connections

Amazon.com

The tape to insulate the exposed wiring.

Amazon.com

 

[Nedwreck]

Can you take a picture around the throttle body? I would be curious to see what the wiring leading up to the connections looks like. Below are the products that I used as well.

The cleaner I used on the connections

Amazon.com

The tape to insulate the exposed wiring.

Amazon.com

CRC is good stuff, I use that myself

My connections seemed pristine really. The rubber gaskets within were great, sealing boots around the conductors look great, everything seemed tidy. Dirty on the outside of course. That said, the screws for the TPS are pretty corroded, I'd be wary of trying to remove them. I'm not sure if I can connect a scanner and sweep range of motion on the throttle body to look for TPS flat spots, with KOEO. Seems like the TB would cycle, just thought about this, I'll try it tomorrow.

I may disassemble these connectors and peek inside.

Is there any pics of the vacuum connections on the back of the intake anywhere? Can't really see anything there, my handy mirror is MIA lol

 

[jman315]

Based on your pictures, I'd say that the connections on mine look much the same in terms of condition and with how much wire was exposed on the end. Shortly after I bought my truck and realized that something was off with the idle after the engine was warm I came across one of @FordTechMakuloco videos where he talked about fake coil packs and how they can cause electrical interference which can lead to misfires. I did replace my coil packs with genuine Motorcraft which seemed to help, but it didn't resolve the issue. That got me thinking that it probably wouldn't hurt to clean up the wiring especially since the original loom tubing and tape is pretty brittle and flaking off on some areas. I would try to put a touch of dielectric grease on each of the pins on the female side of the plugs and then use a good tape up to the end of the connector along with loom tubing. I wouldn't be surprised with as much wire as is exposed on your throttle position sensor if that is the culprit. Here's some pictures as a comparison.


Before

After

 

[Nedwreck]

I'm having a "Doh!" moment over here lol. Exposed wire in my mind is bare copper, but a pic is worth a thousand words as they say. Yep, I'll dress mine up as yours are and see if it has effect. That would be silly if it fixed it, as you said in a previous post.

If I can, I'll try a before and after "Oscope" with Forscan for the TPS and commanded throttle position, just to see if any difference is discernable.