Fairly recent 20% mpg loss. Where to spend $

Best advice needed. I have No tools, no meter. What best to pay for as far finding the cause? O2 sensor test? EGR test? It’s not the gas, as we are in summer blend. Well maintained 121k 2.4l. Something’s up. Forget the usual like plugs, coils, MAS, tire inflation, air filter…forget that…OK? Nothing obvious as far as performance goes. 121k later and it doesn’t burn a drop of oil! Idles pretty nice for a 20 year old truck. Please advise what diagnostic to pay for to get back 20% loss in fuel economy. Injectors professionally cleaned, Toyota factory gapped plugs only 18 months old. Coils not making a tapping racket. Clue me. Please! No DIY stuff. What should I pay for? Too rich gas being wasted? No gas smell from exhaust. I recently ran 2 cans of Berryman’s Total Fuel Cleanup. No change. Humbly submitted. O2 sensor? EGR? What? LOL.

 

Cat getting plugged or exhaust? Or MAF Needs cleaning or defective Will cause

 

Check alignment? Diff fluid? Brakes?

 

Alignment, brakes rubbing, (parking brake set by accident?), cat clogged as suggested

(would see huge loss of performance for most of these)

 

if those are good try a compression test on your cylinders and check spark and plugs.
If your pulling to one side it could be breaks.

 

MAF sprayed with alcohol Easy enuff. I’ll have my brakes checked for free. Never one CEL. Low budget. Pay for what? Recent 20% mpg loss. Can’t figure it out. No offense, don’t mention the obvious

 

Although I doubt the brakes are dragging as they usually smoke and stink, you can check easily for no money.

1) Drive 5 miles or so on a section of road where you can cruise without touching the brakes.
2) When in a safe place coast to a halt, again without touching the brakes.
3) Reach behind the wheel or through it if you have a spoke style and feel the rotor (front) or drum (rear).
4) All should be fairly cool, if you find one noticeably hot you just found a dragging brake.

Something else you can check with just a few minutes and a flashlight - any fuel leaks? There could be a pinhole in a line that only leaks when the engine is running. A mist of fuel sprayed on the exhaust will burn off instantly without any smoke, smell or obvious drips.

Firmly set the handbrake and chock the wheels too before you crawl under the truck with it idling.

Report back & good luck.

 

Actually, I’m somewhat encouraged by my recent fillup. I was getting lousy mpg during the winter gas months. April 1st was the deadline for stations to start using summer blend. It could be that all gas stations don’t have purely summer blend as they refill while winter blend remains in their station’s tanks. It’s over 3 weeks now, so maybe summer blend took that long to completely replace any residual winter blend left in their storage tanks. 30 miles and my fuel needle still above the full mark. To me, that’s an encouraging sign, I hope. I always got lousy mpg with winter blend. Of course, city driving MPG will tell the tale. Appreciate all the replies.

 

gasoline all year is garbage nowadays.

 

have you had any more issues over the past year with this
did it 'self-heal' lol
how was the past winters fuel economy on your rig compared to the last?

i am having similar issues for the past 11k miles after some rather extensive repairs on the old taco but only about a 15% drop that is confusing

 

Not really any worse but not any better. As money is tight, I’ve not the tools nor the money to invest in having various testing and diagnostics done. There’s no real symptoms pointing the way.