lrx300

Long time follower, first time poster:
I have questions for you guys - I did read all the relevant posts for rx 300 codes.
My case:
Lexus RX300 1999. 188000 miles. Bought this in July 2012, has been running great since until last winter when two cylinders had to be changed due to CEL after battery jumping after storm (MI) 3/2014.
Symptoms: CEL On (not flashing) after jumping battery after recent ice storm (TN) 2/2015. Very rough idle, smell of exhaust when it is idling rough, hesitation, and at random speeds engine cuts out like you turned it off and then speeds up again.
Codes: P300, 302, 304, 306, P1354 at the emissions testing center in TN (mandatory testing). went to a repair shop and he ran diagnostic found similar codes and advised to change Both Valve timing sensors and Front/Right sided catalytic converter at an estimated cost of 821$ including 3 hours of labor. he also told me that the exhaust flex pipe/joint has a leak. I then had it looked up at a Midas and they didn't say any of above and advised a tune up and changing spark plugs and gasket and mentioned that i probably may need 1 or 2 ignition coils changed. their estimate was 550$ without ignition coils. I then went to a muffler shop - they told me that there is an early manifold gasket leak which is the reason for noise and will cost 200 (labor)+30-40$ (for gasket) to change it, but it can wait. there is another leak in the exhaust which they will cut and weld in a new sleeve + flex pipe is missing and there is a smaller diameter sleeve which needs to be taken down and a new flex joint has to be installed - cost of these 2 will be 190$.
Now, all this is new to me and i really could use your expert advise and help. please tell me what you would do if you were in my shoes? (i hope not though). also, if something from above does not make sense please feel free to ask, I am really in need of your help to figure this out.
Thanks in advance fellow lexans (is that a word or did i just made it up??)

AnthonyMtz

It's going to be your camshaft sensor aka vvt sensor can be bought at O'Reillys auto parts dorman part# 917-211a for the front for cylinders 2 4 and 6 and 917-214 for the rear for cylinders 1 3 and 5 that failed part almost 100% of the time causes those symptoms I had the same exact issues and it worked like a charm! as for the exhaust leaks you can alway get that fixed at a muffler shop good luck oh and one thing it's recommended to change both vvt sensors cause since one went out the other one usually isn't too far behind , also clean the tiny filters inside

lrx300

but is this a permanent fix or this is temporary i.e. are we dealing with the root problem here?
thanks and please ignore my ignorance...I am new to this.

AnthonyMtz

Lol it alright I would feel the same way, but yes THIS is a permanent fix the reason why you are getting the misfires is because the vvt sensor messes with the timing, if you drive the car like this it WILL cause permanent damage, also your Engine Light will most likely be flashing due to the severity of the problem. If I was you I'd go buy the parts ASAP, I found my dorman part on ebay for 39$ cause O'Reillys wanted 80 lol

AnthonyMtz

I can also sell you my used one, I cleaned it and it works great, just so you can try it and be 100% sure it will work I'll sell it cheap, you can paypal me the payment and I'll ship it to you. Just let me know

lrx300

hi anthony thanks for the offer but I am still trying to figure out whats the next step.
I had the exhaust leak repaired - a new sleeve to replace a leak and a new flex joint/pipe. however, after that the muffler shop told me that the front cat conv is leaking/gone bad and needs to be replaced. but they also mentioned that I will only get the one-year warranty for the new converter if i replace all three cat converters this time. although the middle and rear cat converters have not gone bad yet. will changing VVT sensors still make sense with this new information? I am not sure what should i do nxt? the estimated cost for changing all 3 converters is >1500$...impossible.
thanks

AnthonyMtz

Ok replacing the vvt sensor will fix the misfires, and the terrible idle, I would personally buy the flex pipe and cats and install them myself that price is outrageous!!

lrx300

so the flex pipe and exhaust leak have been taken care of. now, waiting for the VVT sensors/solenoids - droman to be delivered and then will have it replaced. should i be worrying about the cat converter or just wait to see how the VVT solenoid replacement works out?

salimshah

https://www.clublexus.com/forums/rx-...-catalyst.html
Post #9 has the exhaust diagram.

Please refer to this to discuss which cat.

Salim

lrx300

thanks salim for digging this up and for replying to my PMs.
I am wondering if anyone has suggestions on the name and part# for the front cat converter - the one that is close to radiator and goes down to meet the flex pipe. I was told that in my case, that one has gone bad and needs to be replaced.
thank you

salimshah

That would be the WU-CAT.

I posted a DIY on this. Please look at the DIY sticky thread.

Salim

AnthonyMtz

Personally in my opinion I would replace the VVT sensor's first, you can see if replacing them helps, I would wait in the cat.. if you still have issues after the VVT job you will know the culprit. Lol if you were near by I could do the work for you for a really good deal, changing the spark plugs is a breez, removing the trottle body? No sweat, timing belt haha give me 2 hours, I've done it to my Rx my dad's Rx and my buddy's Rx so maybe that's why everything is a breeze, let me tell you this, first time is the worst, second Is the best and third is the very very best!

matts6887

I hear ya on the first time being the worst when it comes to some of the mechanical jobs like sensors, valve covers, plugs, etc. Especially getting to the rear plugs and valve cover. For someone like me who has never done it before it could take me all day to get it done especially getting to the bolts that are way in the back where the rear valve cover is. So Im not looking forward to doing that and I hope I dont have to dig into it any time soon lol

AnthonyMtz

Lol yep, I had to change all 6 plugs 3 times! Cause I got crappy bosch them ngk iridium then ngk platinum iridium lol I had to remove the trottle body 3 times for cleaning and for the rear plugs and it just gradually got easy haha

matts6887

Speaking of that; I will pm you if i need help getting to the rear spark plugs/rear valve cover area at any point down the road so as to keep this topic on the straight and narrow so to speak. But for right now on my rx300 everything is peachy