New member - P0299 turbo underboost

[matthew9848]

Bought 2019 Ram 2500 Bighorn diesel with 21,000 miles on if. Turbo underboost P0299 has been reflashed x2. Fuel Mileage drop and some power loss. Been to dealership. All mopar parts. No modifications. Sorry to be a broken record but damn - I’m over this code/issue. I do a lot of interstate hauling. Help???!!!

 

[Brewbud]

I know you mentioned everything is Mopar. Does that include the air filter? Many have had the issue using aftermarket air filters in the stock box. Sounds odd, but going back to a stock filter fixed it. Best of luck.

 

[matthew9848]

All mopar including air filter - I know a few posts back then dealership checked that with another 2019 2500. I heard “Ram” is working on the fix but not available yet. Seems like the P0299 is common out there. I just need it fixed without losing my truck for weeks at a time.

 

[renagade69]

Run without an air filter just to see if the code comes back. If so. Get a spray bottle and check the exhaust joints between the dpf and the manifold. I found a broken flex joint on a sprinter like this. If it's not there it's an intake side suction leak. That code is usually a leak somewhere. Don't spay soapy water on the intake side.

 

[matthew9848]

Thank you. I’ll try today.

 

[AKDoug]

We've got a four page thread on this already. https://hdrams.com/forum/index.php?threads/2019-ram-2500-6-7l-p0299-code.2164/

I've got the same issue that started at 43,000 miles and it is on its third trip to the shop. The new verdict is that it needs a new EGR valve, but they are on back order for over 100 days. I think they are grasping at straws right now. I'm leaving in a few minutes to go get the truck. I'm going to pull the EGR myself and clean it. It's worth the shot and I'm only out $100 for gaskets. Wish I could help you, but I can't.

 

[AKDoug]

Update.. I pulled the EGR back in July. Clean as a whistle and totally different than previous generation EGR's. I basically haven't been able to tow over 5K since April without the trucking getting stuck only making 11 lbs of boost. I've been driving my '06 Duramax for towing duties since then and I now have zero clue why I replaced that truck.

 

[Wileykid]

Well, I just joined the P0299 club. I was able to pull my trailer the last 100 miles to my destination with the light on, and took it to the dealer near where I am at. The mechanic (only factory diesel mech within over 100 miles), said he reset the computer, but light came back on. Earliest they can get into it was next week, and what parts may be needed, could be several weeks+. Computer updated to the latest, and drove back to where I am staying, and the light is off for some reason. I have an aftermarket air filter on it, that I changed about 1,000 miles ago, and it replaced the same brand that has been in for about 14K miles. I can't wait several weeks, 600 miles from home, so I will try and find a MOPAR air filter, put it in, and early next week, pull my 14.5K lb trailer home. Got a couple of good hills to climb (Ashville to Knoxville), so hopefully I will make it home.

 

[jkempken]

Well, I just joined the P0299 club. I was able to pull my trailer the last 100 miles to my destination with the light on, and took it to the dealer near where I am at. The mechanic (only factory diesel mech within over 100 miles), said he reset the computer, but light came back on. Earliest they can get into it was next week, and what parts may be needed, could be several weeks+. Computer updated to the latest, and drove back to where I am staying, and the light is off for some reason. I have an aftermarket air filter on it, that I changed about 1,000 miles ago, and it replaced the same brand that has been in for about 14K miles. I can't wait several weeks, 600 miles from home, so I will try and find a MOPAR air filter, put it in, and early next week, pull my 14.5K lb trailer home. Got a couple of good hills to climb (Ashville to Knoxville), so hopefully I will make it home.

I had the same code pop on me headed to the Black Hills in South Dakota from Wisconsin for a UTV trip pulling an enclosed trailer with 2 Rzrs. Didn't really notice any power loss or anything but the check engine light stayed on the entire trip ~1000/1600 miles. Got back home and the next morning when I started the truck up for work it was gone. Validated it was still stored with my scanner and took it to the dealer. They flashed some new software in it and sent me on my way. Link for sticky https://hdrams.com/forum/index.php?threads/vehicle-performance-tsb-18-012-21-rev-a-rtt-21-027.4507/

 

[Wileykid]

Made it home without the light coming on, sure wasn't fun wondering the whole trip if it would come on or not, and was being as gentle as one can be with it. I bought ($$) a MOPAR air filter and replaced the one I had in the truck, prior to leaving. Going to talk to the local dealer, and see if they could tear it apart (under warranty), and make sure everything is okay, although I pretty much know the answer already. Have a 1,200 mile, non towing trip coming up in a couple of weeks.

 

[RamCares]

Made it home without the light coming on, sure wasn't fun wondering the whole trip if it would come on or not, and was being as gentle as one can be with it. I bought ($$) a MOPAR air filter and replaced the one I had in the truck, prior to leaving. Going to talk to the local dealer, and see if they could tear it apart (under warranty), and make sure everything is okay, although I pretty much know the answer already. Have a 1,200 mile, non towing trip coming up in a couple of weeks.

Hi Wileykid,
If you need any additional assistance alongside your dealer, feel free to send us a PM.

Sarah
Ram Cares

 

[coreshot]

Just wanted to say thanks for the posters here. My '21 has 15k on it. I replaced the air filter at 10k with a Mopar one at 10k after driving through wild fire smoke last year that caked the original. I just took the truck in for the 15k service where they replaced the air filter even though I told them not to. drove home fine. I leave on a work trip for 3 days and my wife is driving it and the CEL comes on with this code. After reading this, I check the air filter and it's an STP air filter the dealer had put in. I don't know if this is correlation or causation, but it has been going into Regen a lot more than usual lately and mpg are down about 2mpg from the norm. Called the dealer and they're sending me a Mopar filter