Need some wrench help -- replaced back 3 plugs AND coils [2/2023] and front 3 plugs only -- NGK6619-plugs; NGK48726-coils. Did not replace the front coils. RX started to run rough, threw first code of P0351; replaced front 3 coils and now throws code of P0353 -- Ignition Coil C.
Any ideas?

 

Read the code and do a controlled swap of coil from bad cylinder to good cylinder. If the problem moves then replace the coil. If it does not move swap the plugs to confirm the plug is the problem.

I only purchase parts subs as Denso plugs from authorized dealer.

Salim

 

Many thanks 4 the prompt reply and advice, Mr. Salim; really wasn't jumping up for removing the plenum etc., again to get at the back plug/coil row. Got the plugs/coils from RockAuto -- NGKs were a little more expensive than Denso and had the better warranty.
Bummer -- got a weekend job to do.

 

Nothing wrong with NGKs as they are OEM as well. Only concern I have is with sourcing from dubious sites. Rock Auto is reputable.

Salim

 

This is a very useful post as I am about to do this job, including replacing the back three coils. Replacing the front coils is so easy, I think I will test the three new coils in the front for a hundred miles before moving them to the back.

M

 

One of the potential issue with removing the intake and plenum is the gaskets giving way. Factory procedure recommends replacing them.

I was too lazy or not motivated enough to try to replace the back spark plugs without removing the intake on my 450-H.

Salim

 

Any gasket brand recommendations? Remove/replace just the plenum gasket—any other things I should R/R pay attention to while I’m there?

 

Off the topic of plugs/coils, never had the tranny fluid replaced/flushed—125k, 2010 RX; stealer or local shop able to handle?

 

Do you know if it has ever been changed? Does it shift and operate okay now? If so, it is probably safe to change it, but a couple of drain and fills a week or 2 apart is a bit safer than a full fluid exchange at once.

If you have a well regarded independent Toyota specialist or transmission shop try contacting them first to see what they offer and how much. See below for details.

Next Call around to Lexus and Toyota dealers regarding the transmission fluid change. Some dealers will do it and others will say never touch it. You want to find one that will change it. Find out if they are doing a simple drain and fill, or a fluid exchange. If a fluid exchange ask if they are using a BG machine or similar device, or following the Toyota/Lexus method. Many members use Toyota dealers for service.

 

No tranny shifting issues—I’ll call local
Toyo shop; corner tranny guy is stout. They replaced wife’s 2008 RAV4 tranny and PCM unit; $4k.
And, hate to be a PIA, the RX plenum gasket issue?
Many thanks, Clutchless!

 

Just get OEM. You need three. They are not expensive. Just make sure you get the newer orange ones. Might as well replace the throttle body gasket as well.

222710P020 Fuel Injection Throttle Body Mounting Gasket x1

171760P021 GASKET, AIR SURGE TANK TO INTAKE MANIFOLD x3

 

If NGK coils were a bad purchase, would it be recommended that I swap NGK 48726 coils w/ either Denso 6731309 or OEM; can’t keep dismantling the back coil/plug row??
Never thought that swapping coils/plugs would be so crazy.
🤕

 

Do the series of three cold ATF drain-and-fills yourself. Excellent step-by-step instructions are posted here on the forum. It is a very easy job. If you can change the spark plugs, you can do the ATF drain-and-fills.

 

This link is to the giant transmission fluid change thread which includes instructions on how to do a cold drain and fill.
https://www.clublexus.com/forums/rx-...d-threads.html

I will summarize it as I have been doing this procedure for almost 15 years.
You need a 6mm Allen wrench for the pan drain plug and inside the drain hole is a plastic overflow tube that also takes a 6mm Allen. You have to be very careful when replacing the overflow plug to gently screw it in until it stops and then leave it. You don't want to break it and there is no need to tighten it more. The fill bolt will keep it in place.

The fill hole is on the side behind the driver side front tire which must be removed. it takes a 24mm wrench. To get to it you remove a little flap on the fender liner that has some plastic plugs and a 10mm bolt or so. You need a funnel to fill it up.

I think the correct amount of fill is 2.25 quarts. Once you open the drain plug, a quart or so drains, then remove the overflow plug and more drains. Use a drain pan or bucket with measurements on the side, such as what you find at the paint department at Home Depot or Wal-Mart etc. You need to measure. I found my used Sienna, which as the same transmission to be underfilled by over a pint. It drained 1.8 quarts. It ran better with 2.25 quarts.

Do this with the car off and cold, sitting at least several hours and your new trans fluid at the same temp as it expands when hot. Aside from jacking it up enough to remove the tire and get at the fill hole, you can access the drain hole without jacking it up. Trying to keep it mostly level is best.

I prefer Idemitsu TLS LV synthetic ATF over Toyota WS ATF as it is a full synthetic designed to meet Toyota specs and you can get a 5 quart jug from Amazon. I am running it in all my Lexus and Toyota vehicles.
https://www.idemitsulubricants.com/p...tf-type-tls-lv

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Update ClubLexus--
Reversed the front/back coils -- turns out two [2]were HGK coils back failed; replaced w/ original ones as a temp fix Getting warranty from RockAuto for the 2 coils.
Indey wrench said to replace the 2-coils and get new new three [3] wires going to the front coils.
They replaced the various gaskets as recommended
Recommendation: OEM or aftermarket coil wires??
Corner guy couldn't get at the back plugs; not a job for me in Chicago weather on the driveway.
Indey cost = $300.