Excellent video, my 01 has thrown the 171 code with the 174 pending. As a shade tree mechanic KZfaq has been indispensable especially when you find such wonderfully helpful vids such as yours. Just starting to run down my issue(s), thank you for giving me something else to check, never would have considered looking at the IMRC bushings. Hope it doesn't have to get that far.

I've got a 99 e150 4.2L van I got for very little from a friend of a friend, same codes. Your video is helping me familiarize myself with the 4.2L, so thanks for the video. I so miss the 300 I6's! Thanks again.

Thank you so much, this video was a huge help. I was able to replace one of the retainer bushings and bank 1 without removing the upper manifold. It was a pain but your video helped a ton. Thanks again!

This video has helped tremendously. I have an 04 heritage(pretty much an 03) with this motor and those code but no imrc codes. I'm looking forward to tearing it apart here soon and cleaning up everything I can.

Thanks for sharing. I had to laugh when you said, “I hope the gasket wasn’t compromised” after wrenching it into position. I too say the same thing.

Great video. 👍👍👍👍 Tons of useful information here. Wise decision to do everything you can while it's opened up.

Top-notch video! Thank you. Also, pat yourself on the back for replacing those heater hoses while your intake manifold was out. Just did that with manifold in place, and boy was it a pain.

You're a patient man. I bought a 1999 E-250 with that motor AND those codes. Drove it weekends for a couple months to finish the job I was doing; sold it for even money, never bothered to fix it. (Like you said, it ran fine.) I imagine it's easier to do this job on an F-series, but still... You're a patient man.

I thought for sure the gasket got compromised looking like a race and very rough install..i'd bet is the reason the light came back on. Thanks very much for the detailed work with part numbers, part names and locations!! Other sites were useless and I now have all I need to do the repair myself. I bought an 03 and a few days later noticed a small pool of coolant at the top front wondering if the intake or water pump now it might be a rusty coolant pipe the 90 degree one especially it's in that area and the truck came from Illinois and was in Hawaii a few years and has some rust which being in Vegas rust is rare. I don't have a check engine light on (yet?) after 100 miles and it passed smog. Great work and info you did thanks as I like to do everything myself. Liked all the comments and will use the motorcraft grommets you mentioned. TY TY TY!

Thanks for the video. I'm about to do the same repair. Smoke test indicates the lower intakes gaskets failed. Research indicates the Ford bushings (4) are better to go with even though 4-5 times the cost. Hope you have good luck with the HELP brand. Again great info brother.

I just did mines thank to you sir. My imrc links were both off

Best I ever seen. Thank you. Great video sir.

You got to have a lot of patience to do all of that. And a good amount of mechanical skill from over the years. Looks like South Jersey somewhere. I'm from New Jersey as well around Edison

The lean code was probably just the isolator bolts. Super common problem. No need to pull the lower manifold. Extra work. Just mentioning for future people who come across the video. The earlier 4.2's had lower manifold issues, but by 2003 those were gone. Ford isolator bolts are still available. Probably much better quality than Fel-Pro and Dorman. Surprised that you chose Dorman over Fel-Pro also. Strange. Anyway, good luck, and thanks for posting a video.

Really very helpful. Thank you. Any issues with the injector electrical connectors? All of my retainer clips to secure the connection kept falling out.

Just performed the same IMRC fix. (Bit easier w a rearview of the engine from an E250 doghouse, lol) but unbelievable the codes thrown from a 10¢ plastic bushing failing & popping off. Any Ford owners experiencing rattling & loss of power under acceleration, I'd advise 1st take a peek at your IMRC actuators before spending tons of time & money. Not a lot of info on it out there besides "check your heat shields". 5 pack of "Dorman vacuum retainer bushings" for $10 (part# 47099), will save you a ton of headaches.. (Couldn't watch the whole video, but thanks for getting that part out there! 👊😎)

Great video. I have an 05 with a P2006 code (IMRC stuck closed) it runs fine and no check engine light, Think I'm going not just leave it alone.

That's a beautiful truck

What those 2 silver hoses behind upper intake is that the fuel return regulator

I have a 2003 f150 4.2l i always replace the upper plenum gaskets along with the isolated bolts one thing i eember is that qhen u bolt down the plenum gaskets it has it oreder or else that code will come back

Thank you a lot... I have one plastic broke .. replace both

I have the same problem with those plastic things breaking. Did it fix your problem?

I have a 1999 F150 with the 4.2 engine. I was wondering where the cover is that belongs on top of the fan shroud. That opening will allow air to go around the radiator instead of being pulled through. I have one but the truck you're working on doesn't. Just asking!

Would you know if this IMRC valve could be the reason for my muffler being glowing red hot and power loss , and erratic idleing , and strong sent of gasoline

What about the seal around the lever that goes into the manifold. Those seals wear and leak and trigger the lean codes.

I'm having the same codes with my 02 4.2 liter. Too bad you can access them with out pulling the manifolds

I have the same codes on my 2003. How long of a job is this? Any other surprises? I'm in DE so it's not passing either with the light on.

Great video Buck. It gave me hope today that I might do the job myself. I have a great running 1997 F150 4.2L V6. HOWEVER, it is throwing P1513, IMRC2. "STUCK CLOSED" After research I believe the plastic clip on the passenger side Right Bank may be accessible to pop in if it did indeed break. I have also learned it could be a vacuum solenoid not deenergizing above 3000 RPM - upon which the vacuum is then released allowing the butterfly to spring open. if I remove the power assembly connected to the right of the battery on the fire wall might I with a mirror see and access the clip housing for the rod? If not it becomes a trade off between a price to have a good shop to the job plus a little more vs. me doing in the driveway! Rain makes me wonder if I can or should remove the hood should I do such a project? What is a fair price to have a good shop replace both IMRC Banks 1 & 2? PS, I took all the AC crap out when I purchased the truck 3 years ago so I have some increased accessibility to the BANK 2 area. But it all seems daunting to actually try to fix it without pulling off the manifold! And that is no easy task for a 1st time pull off project like you just did. Thanks for your help as my inspection month is Feb. 2023! From Cape May NJ.

Great video! I am suspecting this happened to mine as well. I have a 2004 ford mustang 3.9 v6 and it does have a TSB on this issue. I can not see back there...I tried mirrors to no luck so I think I'm going to take the plenum off and see from there....can I see when I take the plenum off or will I need to take the lower intake off as well to see? Also did you notice a slight shake at idle with this issue? I am noticing a slight shake at idle and my trims aren't terrible but not good either bank 2 is +11% at idle while bank 1 is +4

I understand that the 6 small plenum gaskets need silicone lube to make them last/seal correctly.

Good video having same trouble. What was cost for parts. How long did it take u to complete job. Very clear video.

dont forget to replace the isolater bolts and new grommets.

Bought an 03 with 174,000miles.. around what miles do these usually fail? Hopefully they've been replaced already. I noticed the smell of coolant and see some pooling above the water pump the weep hole always dry..the heater core hose is right there too and has a radiator clamp that was loose i tightened..all good now but will keep checking..

I just got done doing this job and when I turned the truck on I had a code for P1518 runners stuck open I even installed a new actuator 🤦🏻‍♂️I was devastated that I now have to take it all apart and figure out why it’s not working

Can the module go bad because I just replaced those white bushings and it’s still throwing the code?

Was that p0171 and p0174 the only codes you were getting from the truck. Because my truck the same year make and model is giving off 5 codes (p0303, p0171, p0316, p0304, and p0301) I was wondering if you think that code would also cause those 4 misfires that I am getting. Would hate to waste more money trying to figure this one out.

Hi I have a 1998 Ford F150 with the 4.2 V6 and it's got both codes P0171 & P0174 so what you just did to yours do you think that might be the problem with mine and yes my truck seams to be running fine the only thing that I am concerned about is the gas mileage will those codes cause my truck to burn more gas than normal ?

I've had my 97 for about a year now. I've been involved with it since 97. My father in-laws old truck. I have all the maintenance records. Everything is cherry. Only 132k miles now. Bought it with 128k. Anything I should keep an eye out for? Same motor. 4.2. Still can't believe I only paid 3k

If you we're to guess - What's the approximate swap time on just doing the plenum & isolator bolts? (won't you to it, lol. Just an approx), thnx

What did you use to clean all the ports?

So what happens if you don't replace the metal rubber gaskets

do you know how to fix a po code 174

Replaced these clips twice already. Keep warping from heat and popping out.

What does it affect, or can the trucks run well?

But you never got the P2004 IMRC Code? you only got the system to lean codes?

Gd job

Why couldn't we just open the butterflies permanently and leter eat!

Good job I have a econoline van with the 4.2 if you think the 5.4 is crap this had to be the worst motor ever put in those vans I had all these problems and more from this gutless motor.i cursed ford out and bought a Chevy

where can i get the intake manifold bolts at? i tried to use the old once and i didnt even get to 15 pounds and one broke.

I have a nm torque wrench, should I be using a 5nm or are they the same

Just did the upper manifold gaskets...AGAIN...had p0171and P0174..was a vacuum leak cuz whats the chance BOTH O2 sensors go bad at the same time?? ...Had the IMRC issue too with those stupid plastic clips..another code for that! Still, love my truck and even though it's slow and can't haul a house, she's a reliable, smooth with a 5 spd, still fun to drive!! Nice video, nice job!