Halogen or HID.

Normal perimeter/interior lighting is fine unless you're running halogen backup lights.

 

Some of the higher wattage incandescent bulbs get fairly hot, not a bad idea to wipe them before installing but also likely fine if you don't. A 194 won't be of any worry, but if it makes you sleep better at night clean before installing.

 

Nice. Thanks. I just put it in w/o cleaning. Now my driver-side side marker light finally works again. It has been bothering me for a while. It is kind of funny that a lot of Camry I have seen have one or both rear side marker lights out.

Here is a link from osram with a list of all the bulbs for 2001 Camry.
http://www.osram-americas.com/en-us...e-lighting-systems/Pages/lrgallbulbs.aspx?year=2001&qual=245&model=920&make=108

I do not have courtesy lights on my car. I guess it must be an XLE option. But how about daytime running light? I have never heard that 4th gen Camry has DRL. What is going on here?

 

For all the 168 (194/2825) except brake lights, I used the sylvania leds. The chinese generics burnout quick.

 

I read somewhere that LED can only be used to replace interior bulbs. Exterior bulbs are safety related, and LED upgrade might not meet the safety standards. Therefore I just used normal incandescent bulbs. Is it true?

Also this baby on Amazon has about the same number of review as the Philips one and the review are similar. Have you tried this one before?

https://www.amazon.com/Yorkim-Gener...0JRE38EA/ref=sr_1_4?s=automotive&ie=UTF8&qid=1488519907&sr=1-4&keywords=194+led

 

Its not good to use the canbus kind. Regular is ok for some not all. My avalon 3rd brake light cannot handle the led (voltage diff) so it shows light out etc. Can type would work but not worth it, as these old cars were made to handle incandescent. Thats why use where applicable (small stuff) but not just to switch from regular to led.

Trunk also takes these bulbs. I used them only for the park/marker in honda, nothing else. As for interior, I switched to leds in the honda but have to order for all you toyotas.

Have not tried those yet but look nice. I still have about 11 of the generic 168s left to use up.

 

What kind of light bulbs cannot be touched by bare hands?

Hot ones.

 

LED exterior replacements can cause a few different problems.
Brake lights often result in non-functioning cruise control (system thinks the light is on), as well as ABS issues (no speed reduction with brake application).
A newer issue is the Toyota "floormat recall" programming cutting the throttle to idle when the brakes are applied at more than 30 or 50% throttle.

These monitoring systems generally use ground-true logic, and the sensors require a small amount of current leakage through a filament to properly sense the status.
A load resistor can get around these issues, but then if the light actually does fail, there is no indication of a problem. The resistors also generate a lot of heat.

The CANBUS units may also work, but some Toyota turn signal sockets are not wired for them. The front turn signals on the Tacoma are an example... OTC LED units will blow the circuit with a direct short to ground.


As far as seeing a lot of Camrys with the rear market lights out, that's because people generally don't bother to check.
Every couple of months, go to a parking lot in front of a store with large windows after they are closed and drive a circle while checking your markers and brake/turn signals.

 

As far as seeing a lot of Camrys with the rear market lights out, that's because people generally don't bother to check.
Every couple of months, go to a parking lot in front of a store with large windows after they are closed and drive a circle while checking your markers and brake/turn signals.

Many Camry...if not all Camry do not have a 'rear light out' indicator anymore. I think Toyota stopped with the Gen5 2002+. IIRC, every Gen3 and Gen4 had the burned out lamp indicator except maybe for the 'DX' or 'CE' trim.

 

Halogen light bulbs: oil from your hands shortens the life.

 

Any bulb that gets hot enough to use fused silica as its glass needs to avoid your fingerprints, and that includes both HID and halogen bulbs.

Its actually the halogen salts (sweat is salty) in your fingerprints that catalyzes the devitrification of the silica (literally "deglassification"). The silica becomes more crystalline and thus weak so the bulb can shatter. Its not just the oil, a spatter of silicone spray or other pure oil probably won't mess up your bulbs, its the ions in your sweat. Salt in general would be similarly bad so I suspect halogens might fail more frequently where they salt roads, although the finger oil might hold the ions close while it heats up.

A halogen bulb (or fused silica quartz crucible) can get a beautiful etched fingerprint after it heats up but is considerably weaker and may fail shortly thereafter. The glass is only tough because its amorphous and introducing a crystalline structure makes it brittle and weak.