Firstly, wanted to check the condition of my plugs since, my 06 has been running poorly. They were changed 3000-4000 miles ago. Correct me if I'm wrong, but these are the wrong plugs? IKBH20TT They should be FK20HBR11 correct? Or are they interchangeable?

Secondly, This hole on the intake tank?!? That's not suppose to be there correct? It looks melted or is that just from the mold?

 

Your car is a 2006 gs300 correct? Just wanted to know for verification.

Those two spark plugs are interchangeable. One is a high performance plug (change every 30k mi), the other is a Long Life plug (every 90k mi).

Also, that hole seems fine. It's not a melted spot on the runners so it doesn't seem to be bad (don't quote me on that, as I don't own a GS300 so I can't tell you if it's okay or not)

From a picture observation it looks like that hole is supposed to be there.

 

Thanks, I suspected they were interchangeable, but was thrown off by Amazon saying they aren't compatible.

I thought maybe I had a break through... ugh... back to square one.

 

What symptom is your car showing?

 

Slight power loss at times and RPM dropping and jumping up while driving at lower speeds. Going to get the Transmission fluid flushed Friday and start replacing sensor's one by one I guess.

 

Who did your spark plugs? OEM plugs are the long life plugs. If you purchased this car used and those plugs came with it, it only lasts a good 30k before it's useless. I'd change them anyways.

 

They were supposedly changed by the dealer just before I bought the car 3000-4000 miles ago. I only pulled the one pictured, and I'm not a mechanic, but it looks like a fair amount of carbon on it. I plan to replace them with the performance plugs in the spring after a top engine clean.

 

Sounds good, GL to you!

Also, I still hope you noted that hole.. Like I said, from pictures it doesn't look its bad, but it could be and you don't want to keep driving on it. (I own a GS430 so my intake manifold's a little different).

 

Pop the hood and take your V-bank cover off, then start the car. Go back to the engine, and see if you can hear a suction/vacuum noise coming from the hole. If there is a noise, cover the hole with your hand and see if it goes away

 

That was the first thing I tried. Didn't notice a difference. I found a few parts online and they look like that, so I guess its normal. It's just strange. You can see down inside there with a light.

Is that yellowish part the idle air control valve?
From this diagram it seems to be, but I read the vehicle doesn't have one??? Can it be taken off and cleaned?

 

Wrong plugs. Whoever said its interchangeable is incorrect.

There was a debate about this years ago.
The finally verdict...the high performance will damage your motor.

Please change out to the factory oem ones.

 

Luckily your car hasn't overheated. These are the correct one to use on our 2006 gs300

 

just throwing this out there. different vehicle, different motor, same issue.


low power in a specific RPM range.

changed the plugs and plug wires, no difference
changed the 02 sensors, a bit of an improvement
changed the Catalytic Converter, problem gone.


this was on a 1995 4runner 3.0 with 236,000 miles.

 

looks like the idle air valve is held in with two bolts, so I would be surprised if you couldn't remove it

 

It's probably not the cats, OP would almost definitely get a code if there were anything even remotely wrong with them. The damn sensors are so sensitive you're more likely to get a false positive than a false negative. My dad's 2GS had a P0430 a month ago and the indy shop quoted $3850 for the OEM replacement (I don't remember what the quote was with labor). I replaced a few exhaust gaskets ($40), he got the code cleared, and he's driven 300 miles so far and the CEL has stayed off

Were your cats clogged?