The only spark plugs you should ever put in your Toyota with a 3.4l engine is the Denso or NGK dual electrode OEM spark plugs. Do not mess around with Bosch, Autolite, or any other brand they try to sell you at your local auto parts store. You will run into misfires, possible head damage, and regret ever putting those plugs in your car. You may think that this is an old wives tale, but I am here to really warn you. DO NOT put any plugs except the OEM dual electrode plugs in a Toyota 3.4l engine.
I will be making a video shortly, but my friend’s car has the bosch plugs in it. It is a 2001 Toyota Tacoma with the 3.4l and only 80,000 original miles. When I drove her car, I drove it like I normally do (to test a car out) and I punched the gas to the floor to see how it handled high RPM’s.
It immediately misfired, and violently, above around 4,000 rpms. Like it was hitting the rev limiter (but still had a thousand RPM to go before even getting close).
She felt it too since she was in the car, and then she stated she started noticing it after that more often. It is downright dangerous when passing cars on the freeway or up hills, but around town, it drives seemingly fine.
Just the second you start really asking it to go, it starts misfiring.
She took it to her mechanic since I didn’t have my tools on me. He pulled out the plugs and told her they looked good, and that the misfire was “normal.”
Well, not being satisfied with that answer I pulled one of the front plugs and guess what I found?
A bosch platinum +4 plug.
Immediately I knew this was causing the problem. I had seen this before. In my old toyota tacoma that had the 3.4l someone else had put these plugs in the car.
It would drive fine if you never really asked it to accelerate very hard, but the second you needed to make that scary merge on the freeway it would start popping and misfiring.
Here is a whole thread of people on a forum having problems with Bosch plugs in their Toyota 3.4l’s. Oh and another different thread.
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I am super tired of people even debating this online. The fact that anyone would ever recommend to you to put anything in your engine beside the OEM Spark Plug (when others are known to maybe cause problems) blows my mind.
As a great example of malpractice. This video of these guys who come up in YouTube for Toyota 3.4l Spark Plug Change.
Installing single prong Bosch plugs. When the vehicle clearly states no single prong spark plugs!!! It says that in the engine compartment!
They also used no anti-seize on the new plugs. I cringe watching.
I will save you the headache. Avoid the bosch plugs in a toyota 3.4l like the plague. Someone from Bosch want to take offense to that? Please contact me on my “get in touch” page– I’d love to hear how I am super wrong!
Coming soon! A video of my friend’s car that currently has the bosch plugs in it. I will show you how it misfires, how the plugs look fine to the eye, and how once we change them back to the correct spark plugs the car will run perfectly again!
What are the right plugs for a Toyota 3.4l 1995-2004?
If you want to be 100 percent sure you are getting the right plugs call your local Toyota dealership and ask for the parts department. Give them your VIN number and ask them for the spark plugs. If they’re being nice you can ask them for the part number (correct,) and then order them online.
Most part stores will not usually give out part numbers, because they know you can look it up online and save %50 off of their prices. Dealerships have crazy high markups. If you’re going to be buying plugs or any parts at a dealership you should always ask for a discount. They will pretty much always give you at least 10-30 percent off just if you ask nicely.
Push a little bit harder and they may drop the price by as much as %50. Not always, but worth a shot.
Here are the correct plugs for example for a Toyota 3.4l Toyota Tacoma Year 2001. Yours are probably similar if the engine is a 3.4l for sure.
How Often Should You Change The NGK / Denso Plugs In A Toyota 3.4l?
Every 30,000 miles with these type of plugs. Don’t worry about changing the plugs on the 3.4l is really straight forward. It is a good practice to do often anyway. Spark plugs are cheap and honestly worth replacing often to get the best gas mileage and performance out of your truck.
Should You Apply Anti Seize To The Plugs?
Yes, I believe you should be applying Nickel anti seize to all plugs on all cars. I don’t care if they have a coating or not, it is good practice in my book. A little bit goes a long way. To buy the best anti seize in 2018 grab this bottle off Amazon. It is Nickel based (rare to find) which means it won’t react with stainless steel, and it conducts electricity well. Click here to check the current price on Amazon.
If you want to read more about the correct way to use anti seize based on how they maintain aircraft read my post here.
What Kind Of Spark Plug Wires for a Toyota 3.4l?
Once again go with NGK or Denso spark plug wires (this NGK set is OEM grade and well reviewed— links to Amazon). OEM is best for any car and any spark related component.
If you have to replace a coil, please replace it with another Toyota OEM one. The cheap ones may work for a couple years, but diagnosing a weak spark due to a crappy coil is a lot harder than just putting the right one on in the first place.
Want to save some money?
Don’t buy the coils new, get a used coil set from eBay. Or go grab some from pick-n-pull. I do this all the time and constantly keep at least one extra coil so that I have a backup. You do not need to always buy brand new parts. You also do not need to be replacing coils as part of a preventative maintenance plan. Save your money. Replace parts when they’re actually bad. Especially easy to get to and change parts like a coil on plug in the Toyota 3.4l. Takes about 5-10 minutes to change.
If you do want a new OEM Toyota Coil because you have one that is bad. Then this one on Amazon is what you should buy. Or just go grab one at the local junkyard or off eBay.
Click here to read my article on how to properly use anti seize on spark plugs in 2018. It isn’t as easy as you might think.
How To: Change The Plugs on a Toyota 3.4l from 1995-2004:
Things he used in the video: (All Links Open To Amazon So You Can Check Price / Reviews) I personally have selected these products because they’re the best value/quality for you.
- Spark Plug Gapper (A little different because they’re dual prong spark plugs)
- Silicone Paste (aka dielectric grease)
- Spark Plug Socket Set (I forget the size for these plugs but it is on the smaller side for sure) 90 percent sure it is the 5/8th socket
