Guys - 70k miles on my 2013 GS. I’ve seen other spark plugs come out much cleaner. Do you all think maybe the previous owner used cheap fuel? All 6 looked like this.

Also cleaned the throttle body and it was filthy. Quite a difference in response too after I cleaned it.

 

Really? Those spark plugs look practically new. The center electrodes look absolutely pristine. There's not even any discoloration of the insulator.

Those spark plugs did not need replacing any more than the flip-lid on your windshield washer fluid reservoir needs replacing. If the throttle body and MAF sensor was dirty, that likely helped with the throttle response, but your new spark plugs won't be any better than the ones you replaced.

 

Thank you. I know a lot of you guys say 100,000 miles is the mark to replace these, but I went with the 60,000 mile Lexus recommendation. I know I probably didn’t need it and maybe I’m looking at the bottom of the threads and not at the electrode where I should be. No harm no foul, they’re replaced. Appreciate the feedback

And for sure. The throttle body was pretty dirty. Very dirty.

 

The dirty throttle body may be caused by that aftermarket air intake filter.

 

Good job on the plugs and the throttle body service. Dump that lame air filter and go back to stock.

 

Yep, that aftermarket air intake filter is showing its ugly face in the picture he took of the spark plugs, and likely is responsible for 90% of the dirt in his throttle body.

 

The intake has only been on for the last 500 miles. This TB was filthy. Like years of crap.

 

Really? This fast? The intake has only been on for maybe a month and I drive the car 2-3 times a week.

 

I very much trust you guys and your recommendations. You’ve all (and you especially) have helped me a lot since I got the car. Maybe a quick weekend project to put the factory air box back in is going to happen.

 

Or (1) the previous air filter was inferior or (2) the filter wasn't replaced as often as it should have been, or (3) the car is driven in really dirty conditions if the throttle bottle was as dirty as you say. Throttle bodies get really dirty from poorly filtered intake air. So, where did the failure occur?

 

I can attest that the filter I removed is OEM, but new. No clue if it was previously neglected but the one I’d be putting back in is perfect. The car was in Chicago it’s whole life, so there’s winter dirt and salt. Probably just as dirty as Cleveland…..maybe hahaha. There are service records for the whole life of the car, but don’t see anything about cleaning the throttle body.

 

What brand is the aftermarket intake and filter?

 

It’s a Takeda with an aFe Pro dry cone filter. I heard oiled filters are bad news.

 

Yeah, my buddy's 08 Camry had the K&N intake with oiled filter and his engine got choked and idling weird. We took it apart and spent the whole afternoon cleaning the throttle body and installing the stock intake back and that fixed it. The TB was really dirty too.

My blue FSport filter for this GS is a dry filter, we'll see how good it is to filter out dirt. It is OEM after all and I'd be surprised if it chokes my engine too.

 

I also thought if the oem filter is dry, it’s probably for a reason. I’ve heard that oil can trash your MAF and get into the throttle body. I never thought the intake would do anything more than be loud, but also didn’t think it would cause issues.