2018 TRD Sport, getting 9mpg, super rough idle, terrible noises, and Toyota told me not to come back

Mine is an AT

 

I will definitely do this!

 

Thank you! I was considering buying one of those cheap smoke machines… worth it or just have it professionally done?

 

Smoke coming out of the open filler cap is normal when the engine is hot. Mine does it. There's always going to be a miniscule amount of oil that burns off at operating temperature.

 

Good to know, thanks. Yeah it wasn’t an obscene amount, but just thought I’d add it to the symptoms until I knew if it was normal or not

 

I’m sure it is normal, I just never noticed that on any of my other vehicles.

 

Re: vacuum leak detection
This website was helpful & mentions the smoke machine as an option in finding a leak.
https://mechanicbase.com/engine/how-to-find-a-vacuum-leak/
This sounded a lot like an area that would be of particular interest to you:
4. Solenoids & Actuators
Depending on what type of vehicle you drive, there are a variety of actuators and sensors that rely on vacuum to operate. As one example, the Manifold Absolute Pressure (MAP) sensor needs vacuum, so it can measure the outside air pressure.

If the MAP sensor has a vacuum leak, ignition timing and fuel efficiency are affected. The vacuum leak can also prevent the EGR valve from opening, leading to higher emissions and an overheating engine.

 

This is awesome, thank you very much!

 

As I read through thia I thought MAF sensor could be a significant factor. Cleaning it was a good move, but if the previous owner cleaned it incorrectly with anything but MAF cleaner, it could be damaged. Replacing with new OEM Denso or equivalent would not be a bad move.

 

This definitely seems like a reasonable move. My air filter box looks like it’s not totally closed, is that something that could also be affecting this? Or is this a normal appearance? I think I’ll replace the maf regardless, but wouldn’t mind a second opinion on the air filter box!

 

well I guess a message for ohioans. Something Ohio does better than Canada. Which honestly 100% shocks me

 

That’s how it is.

 

Consumer protection of any form? In Canada? Hahahahahahahahahahaha

 

No, alls good with evap. But I do need to do some more data logging.

Also, the slight steam/smoke from the oil cap is normal when hot on most vehicles. Just certain components of the oil evaporating. Always some Vapors in the crankcase under use at temp. The 3.4 in my last 4runner did that too and it outlasted the rest of the truck lol

By chance, does your truck ever sometimes just randomly drive “perfectly”? Like irregularly well? Usually when it’s raining outside?
Does ECT mode exacerbate any of the symptoms you are experiencing?

 

Before replacing MAF, test it (see parameters below).
Open air box only affects the air filtration and won't affect the engine performs because the issue before MAF.

 

It hasn’t rained here lately, but yeah, it definitely occasionally drives really well, and the gas mileage definitely improves a ton from time to time, but it only ever seems to last for one drive or so

 

Oh shit, mine is way outside those parameters. I don’t have a tech stream, but just a cheapo obd2 scanner. My maf readings at 3000 rpm are more like 50g/s

 

Start with maf.
Cats can cause temp related shit. Amazing you have no codes.

 

That’s the crazy part, even driving with my gas cap off for 2 days didn’t throw a code… but unplugging the maf did, so something weird is definitely going on

 

Driving or parked?