rav3

You can always fill it up & see how many gallons it takes to see how accurate the gauge is.

Boy that is strange to have those go bad. It would make me think there's a separate issue going on. I haven't heard of this from any chevy owner on the forums or YouTube. Wish I had a fix for you.

The vent tube should be on the drivers side under the hood.

Sounds like tge vent tube is bad somewhere. Shouldn't have pressure like you mentioned. That will make it leak.

If tge transfer case works fine, shifts fine & no unusual noise, you probably just need another seal/gasket replacement. If it's not leaking very much, just clean it off, check fluid level & drive it. If it is the seal, try adding some AT-205 per instructions & see if it helps. Do the cheap inexpensive things first is my rule to go by. If that fails, then do the next step.

Personally, I'd clear the code & see if it comes back. I'm curious about your Diablo Tune. What engine & year is you truck and current miles. What was the gas mileage change?

Help clarify to this old man, are you talking about the door lock actuator? or some other actuator?

Synthetic GL5 gear oil is fine for front & rear diff. How many miles on it & did you fill it up?

Can we assume you have had the upgraded ATF SB done.

Can't give much information about this, as I've never done either one myself. I wish there was an easy way to replace the TC. You either need to go from the back (pulling transmission & transfer case or from front by pulling the engine). I'm curious, did you ever do the AFM/DOD dis-engagement with an OBD2 device like "Ranger"? If you have, like I did, I agree with KARNUT above, to skip the DOD delete & TC replacement, since you did do the transmission thermostat delete & changed ATF every 30k. It's my belief the TC goes due to the high ATF temperatures. That's just my opinion. There's lots of videos on YouTube on both of these procedures. What new TC would you put in?

The yellow part looks to be the front diff. locking mechanism. From what I see, there's a very small amount of "seepage & not a leak so to speak. I think you're good.

My personal opinion is...don't do anything for a while. The automotive market, new & used, is heading toward a difficult time. Do a search on YouTube about this & draw your own conclusion. Used cars dealers inventories are not selling. If you look at Chrysler, Dodge & Jeep, their current inventories are quite high, like over a year at current sales. And with the new auto workers contract, price of new cars will be going up. Again, just my opinion. Do your research.

Good luck

To me, it sounds like a faulty oil filter. Try easiest and cheapest things 1st. Replace the filter. What brand & p/n did you put in?

In my non professional opinion, your dealership is throwing parts at it at your expense. You need to take it to a good experienced mechanic that can read you fuel trims & O2 readings along with AFM readings to determine what is not within spec. Also, IMO, aftermarket O2 sensors cause problems. You should always replace with OE. Again, my opinion only.

Search YouTube for this issue. Good resource for problems fixes

Next time it won't start, try tapping it lightly with a steel rod or what you have handy. Also, check you body grounds. Remove, clean & tighten with dome dielectric grease to protect them. If your starter starts after tapping it, you'll need a new started. Been there done it. How many miles? Which engine?

Assuming you have a 6 speed automatic, I think it will drop 1 gear (from 6th to 5th)

Are you locking it first? Also, if the "open hood" latch detection is faulty, it won't work, IIRC.

They look normal from the picture but you never know how good they are resistance wise. https://youtu.be/hnd7P7O_vEQ?si=ydCDLgP-Jq8BdjiY

Looks like your main concern is the front active grill air shutter performance P059F. This may be causing some of the others. This is a common issue. Several videos on YouTube on this. Search & watch the videos to educate yourself on this issue. I will assume it's mad & needs replaced but that my diagnosis sitting in my chair infront of computer. Replace it & then clear codes & see what comes back, if any. That's my .02 cents. Good luck.

https://youtu.be/GDT92HnmkeI?si=DVkMHt4BRK8N-y-5

The RPO code for the Theft Deterrent System is UTJ. Check the RPO codes in your glove box to see if it's listed. The RPO codes list all your equipment that your truck came with

I don't think the Work, LS & Custom trucks have anti theft option. Does your key fob have a panic button?

They system wants to see a certain amount of resistance for the flasher to work at normal speed. Since the LEDs use little current (low resistance) it's throwing a code as if a bulb is burned out. You'll probably need to add some resistance to the circuit. My bmw does the same thing & I had to add resistors to each led signal. That's my guess. Call your supplier for help