Reddit reviews Design Engineering 010378 Fuel Rail and Injector Cover Kit for Jeep (1997-2004, 4.0L Engine)

My heat shield was a disintegrated mess, I removed it and installed my own by custom cutting heat shield tape and the day after I finished they came out with - Design Engineering 010378 Engine Fuel Rail and Injecter Cover (Jeep, 4.0L) https://www.amazon.com/dp/B015NOKWQY/ref=cm_sw_r_cp_api_piyUAbBTGR9HN was not very happy at that point in time.

The first thing you should do is change fluids, then fix the heat soak problem if you have a 4.0 and it hasn't been taken care of. I bought a kit from Amazon that's supposed to be an adequate fix for about 60 bucks which can be found here :

https://www.amazon.com/gp/aw/d/B015NOKWQY/ref=ya_aw_od_pi?ie=UTF8&psc=1

After that, I'd focus on the rust problem. There's a good thread here:
https://wranglertjforum.com/threads/taking-care-of-frame-rust.328/
This is another good resource for questions that you may have:
www.wranglerforum.com

Also, Epstein didn't kill himself.

I went with the Generic 12 hole from Amazon: https://www.amazon.com/TOHUU-0280156161-Upgrade-Injector-1999-2004/dp/B07KWWQXL4/ref=sr_1_fkmrnull_4?crid=32B7CIJNN1XON&keywords=2000+jeep+cherokee+fuel+injectors+12+hole&qid=1554903065&replacementKeywords=fuel+injectors+12+hole&s=gateway&sprefix=12+Hole+fuel+injectors+%2Caps%2C582&sr=8-4-fkmrnull&vehicle=2000-42-347------------&vehicleName=2000+Jeep+Cherokee

But you can go with any from other Suppliers too. all are about the same quality. Definitely a difference in pickup, but fuel economy depends on driving style. Don't forget to replace the fuel rail shield while you have the fuel rail off. https://www.amazon.com/Design-Engineering-010378-Engine-Injecter/dp/B015NOKWQY/ref=sr_1_fkmrnull_3?keywords=2000+jeep+cherokee+fuel+rail+shield&qid=1554903190&replacementKeywords=fuel+rail+shield&s=gateway&sr=8-3-fkmrnull&vehicle=2000-42-347------------&vehicleName=2000+Jeep+Cherokee.

Otherwise, A Cold Air intake with K&N filter and a Throttle body spacer will be some of the first (and least work intensive) performance enhancing things you can do. There is a trade off between pick up power, low end torque and economy that you should watch. A Jeep is not a dragster (not built for it, though the project would be fun) and you don't want the wheels breaking loose when you are on a pile of boulders. Stopping at every gas station you pass is also not a desirable feature....

Have fun!

I had the same code and it turned out to be heat soak. The intake manifold sits right above the exhaust manifold, so on very hot days the hotter air in the intake was causing fuel to partially vaporize in the fuel rail before it could get to the injectors. Fuel can't atomize properly which means its not combusting as completely which can trigger P0455 even with the vapor return line is doing its job properly.

Check all your lines, tighten your gas cap, and buy a $20 code reader so you can reset your check engine code(s) yourself. If the code doesn't come back within a day or so then heat soak could be your cause. I bought and installed this kit and that solved my problem for good.

Installing a new heat shield worked for me when I was having multiple misfires. I was having this issue because of heat soak like a previous commenter said. P303 came back though, so I got a new cylinder head coming this summer.

Try this:
Design Engineering 010378 Engine Fuel Rail and Injecter Cover (Jeep, 4.0L) https://www.amazon.com/dp/B015NOKWQY/ref=cm_sw_r_cp_api_i_1TedBbG7THY43

I found just the larger heat shield for like $20 on eBay but if you want to go all out there is this one.

This is a good kit

https://www.amazon.com/Design-Engineering-010378-Engine-Injecter/dp/B015NOKWQY/ref=asc_df_B015NOKWQY/?tag=hyprod-20&linkCode=df0&hvadid=312684231807&hvpos=1o1&hvnetw=g&hvrand=6194809803259040541&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9030815&hvtargid=pla-570207636650&psc=1&tag=&ref=&adgrpid=60983009663&hvpone=&hvptwo=&hvadid=312684231807&hvpos=1o1&hvnetw=g&hvrand=6194809803259040541&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9030815&hvtargid=pla-570207636650

Might be a good time to do the fuel injector upgrade. Look it up there is a ton of info on this upgrade. Replacing the spark plugs would be good preventative maintenance. If you can maybe run a compression test before you reinstall the spark plugs. I do that to all my new cars to get an idea of engine performance and wear-down.

Design Engineering 010378 Engine Fuel Rail and Injecter Cover (Jeep, 4.0L) https://www.amazon.com/dp/B015NOKWQY/ref=cm_sw_r_cp_apa_ZKl0Bb2F0NPJQ

The long start on hot 4.0 engines is often caused by a heat soak issue that affects the injectors/fuel rail. There is supposed to be a heat shield on top of the intake manifold that keeps heat of the injectors but it’s flimsy and often gets trashed/torn out during repairs. On some 4.0s there are TSBs issued that also call for the injector to be wrapped in individual shields. They make kits for it. I don’t know about your fuel pump issue, but just something to note regarding hot engine starting issues.
Design Engineering 010378 Fuel Rail and Injector Cover Kit for Jeep (1997-2004, 4.0L Engine) https://www.amazon.com/dp/B015NOKWQY/ref=cm_sw_r_cp_api_i_XXEwDb1PVADX9

https://www.amazon.com/Design-Engineering-010378-Engine-Injecter/dp/B015NOKWQY#customerReviews

That's it, I've only heard good stuff about it. But I would do more research on it as a just in case measure to make sure your money is being spent well.