2019 2.7 internmently losing power at high rpms

I have a 2019 2.7 sr 4wd with 58k on it. This started a few months back where I’d be driving usually at high rpm over 3k and would lose all throttle power and truck would just keep dropping until I pulled off highway. Rpms would randomly jump back up but no throttle response at all. No CEL came on. It had a single after market cat on it so took it in and had 2 new cats installed even though the exhaust shop didn’t find problem with the cat. I was getting a cat p0420 code at this point. fast forward and my local dealer had the truck for over a month and they can’t duplicate problem they said but it did happen to them once when they had a valet driving it. Anyways I’ve pulled throttle body and cleaned it. Cleaned MAF and cleaned pedal assemble connector and now it’s back at another shop cause it’s still occurring. Not sure where to go from here. Any insight would be great. Thanks.

 

interesting, did this all start with the aftermarket catalytic convertor? I would start there, since your techs are stumped. Is the replacement OE?
I am not a tech, but taking tend to start with what changed in situation like this.

GL and welcome

 

I bought it used from a dealer and it had one aftermarket cat on it already. It started about 4-6 weeks after purchase. I’ve saw other guys have similar probs on here but it was with the v6 models and was due to the ACIS on the intake I believe but I don’t think that same part is on the 2.7 models but I may be wrong. If it is I can’t find it online anywhere.

 

I’m pretty sure I read a nearly identical scenario a year or so ago. You might do a deep dive and see if you can find that thread and see if OP followed up or if you PM and check status.

 

I’ve searched all through the site and I can’t find anything. I’ve used all kinds of search terms but everything seems to be for the v6 model. I’ll try searching some more tonight when I get home. Thanks for the reply

 

Just take in to a shop with a really high quality two way scanner and some experience working on toyota trucks..they'll tell you what's up

 

thats what I’ve done as of now. Took it to a local shop that says he has a 12k scanner he’s gonna hook to it and drive it til it messes up again. Hoping he figures something out.

 

My gut reaction is to replace the cat with a new OEM part. However, I understand that that’s expensive and is just throwing parts at the problem. Hopefully the expensive scan tool can sort out this headache for you.

 

Fuel filter? A bad tank of gas may have clogged it. Sounds like fuel starvation to me.

 

first dealership said they checked my fuel pump and my fuel system and didn’t find any problems.

 

Replace dry rotted vacuum lines. How many miles on the plugs?

 

Haven’t found any rotted lines and 58k on the truck and I’m sure it’s original plugs.

 

Hopefully your new mechanic finds the problem with his scanner.
Has the in-tank fuel pump been replaced under the recall? If not do it.
https://static.nhtsa.gov/odi/rcl/2020/RCMN-20V012-7781.pdf
Is there any sputtering when you lose power? Water in gas can cause this, however since it’s been going on for months not likely unless you’re using an older gas station with a leaking tank allowing water in- many years ago that’s exactly what happened to me, I changed stations and problem solved.

 

sorry, I could have been wrong. BTW: the search function here is know horrible, so often many perform a search in their favorite search engine for something like "Tacoma World 3rd gen catalytic convertor" to lead them back to threads here.
In this case, I think you are wise to seek the help of another shop/tech, as the dealer you visited doesn't sound capable of properly diagnosing.

 

it’s already been changed from what I looked up previously. And yes I’ve fueled up at many different stations so not sure it would be doing it still for this long. Thanks for the reply

 

Well, don't know how they could have checked the flow rate at the fuel filter. If it is partially occluded it could cause fuel starvation when you are pushing the truck hard and it would seem to heal up on its own.

 

yea I’m not sure just going by what the service advisor told me. It was at Toyota of Burleson in Burleson Texas and they still wanted to charge me a $300 diag fee even though they didnt diagnose anything

 

Let’s try some new plugs while you see if the coil tips are dry or oil covered and take it from there.

 

Thank you. I’m going to give the other tech til Saturday to see if he even gets to it and if not that’s what I’ll try next.

 

I don’t see how plugs would cause loss of all throttle power and then power comes back…