running rough but no code

2105 TRD 4L V6 with 81 k miles was running great then became sluggish on acceleration. I did't get a check engine light and didn't get any codes. I replaced the spark plugs but it didn't make any difference. On the highway is seems okay but acceleration is not normal. This came on very suddenly. I am going to try fuel system cleaners, but any other suggestions are welcome

 

Air filter? Oil level? Did you scan for pending codes? Trac/ABS light on? Some non-engine mechanical (see the purple tank top wrapped around the CV thread)?

 

try cleaning the MAF. Look and listen for possible vacuum leaks. You might need to clean the throttle body, but try the easy stuff first. Check the air intake for rat bastards. Another possible is the fuel filter, but that is an expensive pain in the ass.

 

This first ^

 

Air filter is good, no codes or pending codes, no lights for Traction or ABS, nothing under neath anywhere. Oil level is good, just changed on Friday with the same synthetic oil I always use. How would the oil level make a difference?

 

Will clean the MAF, I will try to look for a vacuum leak. When changing the plugs I removed a line to get it out of the way and the cheap spring clamp on it got bent in the process, I will throw a tie wrap on it, it will work better than the original clamp.

 

I'll 3rd the MAF cleaning. There's a specific spray from CRC that works well, but I've also *cringe* used brake cleaner and had no issues. Double check your vacuum lines, but one would have to be off to create the situation you're describing, and more than likely you'll get a lean code to boot.

 

I will clean the MAF, I jsy happen to have a can of cleaner.
Haha, no rat bastards. tow years ago some squirrel were had her offspring in my heater blower housing while I was away for two weeks.

 

How long since you changed the engine air filter or cleaned the MAF/throttle body?

 

Engine air filter
MAF sensor
Throttle body for carbon build up

If you’re losing acceleration power then yeah your airflow is likely being held up somewhere..

 

There are vacuum lines on the drivers side that usually have to come off (or get knocked off), to get to the spark plugs. It's happened to me before. I would look hard in that area.

 

Looking at the OPs original post, it would appear the spark plug change followed the original problem. That said, a review of vacuum line connections is in order.

Can't help but wonder if there is a driveline issue involved here.

 

Correct, the original rough running is why I replaced the plugs. As far as a drive line issue, I have not unusual noises, it is not shifting funny, it rolls easily when in neutral on a very slight incline.
In my search for things too look at I found lubricating the u-joints video form Tacomaholic which I will do on saturday.

I will be cleaning the MAF when a get a minute when it isn't raining.

 

I suspect your 2015 TRD has one or more zerks on both ends of the drive shaft. I would definitely put the grease gun to them, especially if they've never been lubed.

 

If you have carbon build up in your throttle body your not stepping on it enough. Maybe you got a tank of bad gas.

 

You would be the first person to ever accuse me of not stepping on it enough.
I have been thinking about the bad gas. I filled from about half on Monday and filled from about a quarter today. I also added fuel injector cleaner to 3/4 of atank on Tuesday and at the fill up today. I thin there is a difference but things are still not right.

 

For 2015, does it have the external fuel filter under the drivers side? how is that expensive? Or is it in the tank? I looked up one site and it says 2015 has the external fuel filter.

https://www.yotatech.com/how-tos/a/toyota-tacoma-1996-2015-how-to-replace-fuel-filter-416268

 

From 05-15 they were in the tank

 

I also agree that cleaning the MAF is the cheapest and best starting point. Buddy of mine had a dirty maf from an oiled filter and his truck was hesitating and struggling to accelerate

 

I wasnt sure if it was external...but even at that a 2015 should have problems with the fuel sock...now the fuel pump may be a different story...