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Car Advice Do You Believe What The Dealer Says and More

Car Advice Do You Believe What The Dealer Says and More

Under The Hood show Feb 15, 2026 48 min
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About this episode

The Under the Hood Show dives into a listener's puzzling experience with a 2021 Toyota 4Runner that unexpectedly entered limp mode, raising questions about potential programming issues. The hosts discuss the complexities of modern vehicle electronics, the importance of diagnostic codes, and the role of manufacturer engineers in troubleshooting. With humor and expertise, they explore the impact of environmental factors on vehicle performance and share insights on how dealerships handle elusive problems. The episode is packed with practical advice for navigating dealer interactions and understanding vehicle technology.

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Technical Too Afraid to Ask
Car

Toyota 4Runner

"I have a 2021 Toyota 4Runner. It only has $6,000 miles on it because it's primarily a winter vehicle."

The Toyota 4Runner is a type of SUV that is great for off-roading and is built to handle tough conditions, making it a good choice for winter driving.

Term

limp mode

"And when I pushed on the accelerator, it went into limp mode. And on the dash, it said brake and accelerator pressed simultaneously."

Limp mode is when your car slows down and won't let you drive fast because it has detected a problem. It's a way to protect the car from getting damaged.

Term

traction control

"...where it would go into a little bit of traction control before it would go into lip mode. So the next morning I brought it in again and they were interested."

Traction control helps your car stay on the road when it's slippery, like in rain or snow. It stops the wheels from spinning too fast when you accelerate, making it safer to drive.

Term

reflashed

"...they may have just reflashed everything in the software just to see what would happen. They're like, well, we couldn't find anything..."

Reflashing is like updating the software on your phone, but for a car's computer system. It can fix problems or make the car run better by using new software from the manufacturer.

Term

unintended acceleration

"...the noise from the unintended acceleration challenges that were out there, I mean, we talked about this in the show where..."

Unintended acceleration is when a car speeds up on its own without the driver pressing the gas pedal. This can be dangerous and has led to many safety investigations.

Term

rear main seal

"I have the 17 equinox with the rear main seal needing replacing any tips or tricks. Fix the problem that caused the rear main seal to leak before replacing the rear main seal."

The rear main seal is a part of the engine that keeps oil from leaking out. If it breaks, oil can spill out, which can be a big problem for the engine.

Part

intake

"When you pull the intake off, which is going to be really easy for you if you're pulling the engine, probably 10 minutes, take it off."

The intake is the part of the engine that brings in air. It's important because the right amount of air helps the engine run better and more efficiently.

Part

engine

"When you pull the intake off, which is going to be really easy for you if you're pulling the engine, probably 10 minutes, take it off."

The engine is what makes the car go. It turns fuel into power that moves the vehicle.

Term

drilled out

"but only to the point where the engine will still run fine because if they're too big, if they're drilled out, it won't run properly."

Drilling out means making holes bigger in parts of the engine to let more air in. But if the holes are too big, it can cause problems with how the engine runs.

Term

ports

"But then that tees off to four ports, one in each cylinder."

Ports are openings in the engine that let air and fuel in or let exhaust out. Their size and shape can affect how well the engine works.

Part

throttle body cleaner

"And then spray some carburetor cleaner or throttle body cleaner into that hole and make sure it flows out of all four ports and then blow it out with compressed air."

Throttle body cleaner is a spray that cleans a specific part of the engine called the throttle body. This part controls how much air goes into the engine and needs to be kept clean for the engine to work well.

Part

carburetor cleaner

"And then spray some carburetor cleaner or throttle body cleaner into that hole and make sure it flows out of all four ports and then blow it out with compressed air."

Carburetor cleaner is a special spray that helps clean parts of the engine, especially where fuel and air mix. It removes dirt and gunk that can cause problems.

Part

compressed air

"and then blow it out with compressed air. That's what happens to the engine."

Compressed air is air that is squeezed into a small space and then released quickly. It's used to blow dust and dirt out of engine parts.

Term

back pressure

"That plugs up with a tiny bit of carbon and then you get that back pressure."

Back pressure is when the gases trying to leave the engine have trouble getting out. This can slow down the engine and make it work less efficiently.

Part

air cleaner

"the tube that you see that you're talking about that goes from the air cleaner down to the engine, it's got a little loop in it."

An air cleaner is a part that keeps dirt and dust from getting into the engine. It helps the engine run better by making sure it gets clean air.

Company

CRC

"...you can either use an emission system cleaner kit and use it regularly, you know, about once a year will usually do it, but you've got to spray it in there. It will go into the intake port, the CRC kit we use..."

CRC is a brand that makes products to help keep cars running smoothly. They have special cleaners that you can use to clean parts of the engine.

Term

PCV

"...it's not really, it's a PCV, but it's a passive PCV without an actual valve. It just has those drilled ports, but it'll suck it in there and clean those out."

PCV is a system in cars that helps clean up harmful gases from the engine by sending them back to be burned again. This helps the engine run better and reduces pollution.

Part

injectors

"See, that'll get into the fuel system and it will clean the injectors, which is perfect on that engine too. You do need to clean the injectors, but you also need to go through that intake so it'll pull it through that port,"

Injectors are parts of the engine that spray fuel into the engine for combustion. Keeping them clean helps the engine run better and use fuel more efficiently.

Car

Ford Ranger

"Okay. I have a 96 Ford Ranger and it's a four liter."

The Ford Ranger is a small truck that many people use for work or personal projects. The 1996 version has a four-liter engine, which gives it good power for carrying loads.

Term

code P0171 and P0174

"...I keep getting a code PO171 and 0174. I know it's both banks lean."

These codes mean that the engine is getting too much air compared to the amount of fuel it should have. This can cause the engine to run poorly and use more gas.

Part

mass air flow sensor

"Okay. So I've cleaned the mass air flow sensor. I've cleaned the throttle by just because I've checked for vacuum leaks."

The mass air flow sensor helps your car's engine know how much air is coming in so it can mix the right amount of fuel. Cleaning it can help the engine run better.

Term

fuel pump

"...it could be a fuel filter or a fuel pump. So I put a pressure gauge on it..."

The fuel pump moves fuel from the gas tank to the engine. If it stops working, the car won't get the fuel it needs to run.

Term

fuel filter

"...it could be a fuel filter or a fuel pump. So I put a pressure gauge on it..."

The fuel filter cleans the fuel that goes into the engine. If it's dirty or blocked, it can cause problems with how the car runs.

Company

Road Ready Wheels

"Our partner at Road Ready Wheels has wheels. Thousands of wheels, affordable in stock and ready to ship to you."

Road Ready Wheels is a company that sells wheels for cars. They have many different styles and types, including ones that look like the original wheels that came with your car.

Term

OEM

"Replace or upgrade your damage or plain steel factory wheels with new OEM looking road ready wheels. Maybe steel is the way to go for you to mount a second set of winter tires."

OEM means Original Equipment Manufacturer. These are parts made by the same company that made the original parts for your car, so they fit perfectly and work well.

Term

winter tires

"Maybe steel is the way to go for you to mount a second set of winter tires or you just don't like the aluminum look."

Winter tires are special tires made for driving in cold weather, snow, and ice. They help your car grip the road better when it's slippery outside.

Term

aluminum wheels

"or you just don't like the aluminum look. Road Ready Wheels has many choices for you."

Aluminum wheels are lighter wheels made from a metal called aluminum. They help your car perform better and look nicer than regular steel wheels.

Brand

Mercedes

"Mercedes Cadillac Ford Chevy Chrysler and many more with the OEM fit and look that you want."

Mercedes is a famous car brand that makes luxury cars. They are known for being high-quality and having lots of technology.

Brand

Cadillac

"Mercedes Cadillac Ford Chevy Chrysler and many more with the OEM fit and look that you want."

Cadillac is a luxury car brand from America. They make high-end cars that are known for being stylish and comfortable.

Car

Ford F150

"...I have an 18 F-150 with the 2.7 EcoBoost 100k miles and over the last year or so it started..."

The Ford F-150 is a popular truck that can be used for work or personal use. The 2018 version has a good engine that saves fuel while still providing enough power for heavy tasks.

Part

turbo waste gate

"...now I'm worried it's a turbo waste gate that's acting up on me and so if that's true my main question is how long can I go with this before I think about a repair."

The turbo waste gate is a part of the turbocharger that helps manage how much power the engine gets from the turbo. If it doesn't work right, it can cause problems with the engine's performance.

Car

Ford Bronco

"...m really surprised we have a we have a we have a bronco raptor and it makes noise on startup and we had t..."

The Ford Bronco is a tough SUV that can handle rough terrains and is great for outdoor activities. It was brought back after many years, and people love it for its cool design and ability to go off-roading.

Car

Chevrolet Silverado

"...nd when somebody calls me and says I have a 2019 Silverado and it burns two quarts of oil every thousand mi..."

The Chevrolet Silverado is a big truck that many people use for work or hauling things. Some 2019 models have a problem where they use too much oil, which means you might need to check and add oil more often than usual.

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