Matt Milewski

Hey guys, I am new to positing on this forum but have been searching for years for the wisdom you guys have posted!

I figured it was time to post since I am completely at loss on the issue I am facing. I have a 2009 JKU sport with around 175k miles.

My problems began with the CEL kicking on every now and then indicating the P0404 error code (would turn on and off for a few months). Since all of the shutdowns/isolations happening here on the east coast, I found plenty of time to dig in and start replacing the EGR valve. Upon replacing the EGR valve and cracking every single bumper clip, I put it back together and cleared the error codes.

Probably 200 miles in and I received a CEL with the code P0401 error code indicating a restricted airflow from the EGR valve.

Frustrated by it, I started working on it again and stripped out the lovely fender again just to replace the clips and removed the EGR tube. I sprayed carburetor cleaner on it and wire brushed/used a pick to remove all of the gunk from the side in the intake manifold. Rather satisfied with my cleaning of the tube, I reinstalled it into the Jeep and clamped everything down.

This is where the real fun started. I turned the Jeep on and reset the error codes and left it idling for about 5 minutes. A few minutes into it, the Electronic Throttle Control (ETC) light flipped on and started blinking while the Traction Control (TC) light stayed solid. I assumed this could have been caused by some carburetor cleaner gases being in the tube and when the exhaust was routed through the EGR tube, it caused weird signals in the throttle body. The car idled very hard and seemed to be in “limp” mode in which I could not rev above 2500 rpm when not in gear.

Since this did not trigger any CEL lights, I turned the car off and back on again. The issue still came back a few minutes after being on. I then pulled off air intake and throttle body to check for damage or really anything that looked dirty. The MAP sensor looked perfectly clean and the throttle body did not seem to have that terrible of carbon build up.

My next attempt was to pull the battery lead to reset everything. 30 minutes disconnected and it turned on perfectly with no errors. I decided to take it for a test drive and noticed a slight delay with the throttle response; I would take it out of 2nd gear and the engine would hesitate at 2000rpm for a few seconds longer than normal and then drop down again. I let it sit in the driveway and after another 10 minutes it kicked into the “limp” mode again.

My thought is there may have been dirt kicked through the EGR tube so tomorrow might take it for a bit of a longer drive and ride it a-little harder to see what happens or it it clears up.

Has anyone had any experience with this or any recommendations on how to diagnose the issue? I read somewhere that it might have to do with a dirty PCV valve...I don’t see how that could be related but for the $10 part, I will gladly give it a try!

Any help is much appreciated! Thank you in advance!

Matt

karls10jk

I've had the EGR play games with me in regards to a limp mode and cutting power- most notably on the highway. An air leak presented as a bad throttle body (it wasn't) and I started replacing parts left and right. Further inspection lead me to find loose bolts on the EGR valve at the back of the block. Tightened those up and it went away immediately.

You mentioned you replaced the valve, what brand did you use?

Matt Milewski

Hmm I will definitely take a look at that, it’s such a pain getting back there to tighten the back EGR bolts so definitely could have not tightened it enough.

Only reason I hesitate is because it was running fine (with an egr error code) for over 200 miles now.

I installed the Napa branded EGR valve..actually the second one I’ve put in the Jeep

thanks!

karls10jk

I've seen it run both ways with the EGR code, but the limp mode has me thinking more air. I'd certainly start with verifying the condition of the new gasket as well as making sure the bolts are tight.

It's been many years but I believe the Napa is the one that was problematic for me. I know my current EGR valve is the Carquest brand with new gaskets as I don't recall the gasket being included.

Matt Milewski

Ahh so I think I got it! You’re comment on the air leak really jived with what I was thinking so went right back at it...snapped every single fender clip again (I guess the amazon specials aren’t as durable as MOPAR but it’s a fender after all).

I replaced the egr gasket between the tube and the intake manifold - it was dried out and upon removing it, seemed to have had a crack in the inside of it so could not hold a vacuum. I’ve had good luck with fel-pro in the past so went with them for a replacements.

the gasket between the egr valve and egr tube I replaced as well since I did not want to pull it apart again. I realized the NAPA egr valve supplied a much different gasket material than the fel-pro i installed after. The Fel-pro was more of a cork-like material while the NAPA was much less compressible and some type of composite. Thinking back I recall reminisce of cork material on the valve/tube but thought nothing of it.

Pulling it apart I spent some more time cleaning the tube, focusing on the flanges on either end with a pick and wire brush.

So far I have taken it on for a 15 minute drive and let it idle for 20 minutes with no issues. Tomorrow I’ll take it a bit further but seems quite promising!

thanks again for your help!