Hello all,
I have a 2008 RX 350 AWD running at 150K miles. Recently the check engine light started coming on, which intermittently goes away and then comes back again. The car itself drives fine with no symptoms that I can notice.

I had auto parts use a OBD scanner and the code shown is P0355 and suggests replace ignition coils.
Also additional diagnostic trouble codes are P0300 ( multiple cylinder mis fire) and P0301, P0302, P0303, P0304, P0305, P0306 ( cylinder misfire detected for all 6 cylinders)

I had replaced all spark plugs at 130K miles. This started happening after gas change, not sure if it has anything to do with it or just a coincidence.
If any one has any advise I will appreciate it. I am confused why all the ignition coils went bad together, assuming that is the case.

 

What brand of coils did you replace them with?
Have you checked the connection to make sure they were properly snugged?

 

Coils have not been changed. Spark plugs were changed about 2 years ago, I am not sure the brand. I am not very technical to know how to check the connections.

 

OK sorry I misread thought they changed the coils... coil brands do make a difference. How mechanicaly inclined are you? With suggestions are you confident with doing lower level and have basic tools? With that scan tool were you able to erase the codes?

 

I am not very technical but can give it a try. I do have basic tools. The code scanner tool I used was from auto zone, but I can borrow it from my friend if needed.

 

The first thing would be sure to write down all the codes (which yu may well have already done here)
Next - erase all the codes see if they come back. Anomolies are not uncommon I've seen them many times on several cars
Recommended - I'd remove the plastic engine cover you should be able to access the front 3 coils and likely the back left and right coils you could push to make sure they are solidly connected or carefully (they can get brittle from heat/age so be careful). Do this with the engine cold

Do happen to know how old your battery is? Has it ever been run down and needed to be jumped to start the car? Low voltage can cause "phantom" errors. Even new batteries can be low on voltage from just sitting on shelves at stores. This will walk you through a lot of it...

 

Welcome to Club Lexus and your 1st thread!

 

Thanks for the reply - I had erased all my codes and after driving about 30-40 miles the check engine light came back. The code is still the same P0355.

The battery is about 2 years old, but there has been no signs of the battery being low.

 

First removed the plastic engine cover, just pull it off and inspect for any mouse nest or other rodent damage. They like to eat the wiring! Especially around the coils or fuel injectors on top of the engine.
Based on your posts I doubt you have the tools or skills to replace the rear coils etc. It is quite involved and there are YouTube videos. You have to remove the intake manifold, partially drain the coolant etc, be very careful with wiring, gasket replacement etc. See this YouTube video from the Car Care Nut who is a Toyota Master Tech: One needs to determine what is wrong before randomly throwing replacement parts into the vehicle

 

Hi there - I have a 2007 RX 350. Check engine light and VSC lit. Is throwing P0356 only - from this thread appears I should check the connection to the #6 ignition coil and potentially replace it.

Seems like I got lucky that it was a front row ignition coil….appears to be easily accessible.

But I had also read that the gas cap might be involved - does that need to be tested/ checked? Could the gas cap be the only cause?

Thanks!

 

https://www.clublexus.com/forums/rx-...oil-6-a-2.html

One of many threads addressing your issue. Swap coils, erase teh code, see if the problem persists or if it followed the coil. I see your location shows "ID", if that is Boise Idaho I have a scan tool to use OR can run a full check with Techstream, swapping the coils is extremely quick and easy

 

..

 

Thank you so much for the encouragement. I obviously didn't search enough, still finding my way around the forum website... Also, not sure why my location is ID - I'm not there....

When the check engine light came on I got an Ancel BD 310 and that is how I found out the code.

 

I'm assuming it'll also allow for erasing codes. If you're somewhere technically capable finding $25-30 on Techstream is a good idea works wonderful on our Lexus and should work on most so Toyotas and Lexus for the last 25 years slowed much more info, detailed problem solving, real time days, and also customization (allowed me program a backup key quickly).
Good luck

 

Hi! Wanted to provide a quick update. I swapped #6 and #4 and erased the codes. Then, P0354 code threw, so that was good news, pointed to needing to replace the coil. Did so, reset the code, so far so good! Again thanks for the encouragement.