blckphillp

1999 ES300 part 1 repairs: gen p0420. This is a chronicle of my servicing, for posterity in comparing parts & OBDii codes for resolutions. I am 2 for 2, waiting for parts to solve 3. My 1999 ES300 purchased February at 175,000 miles from Lexus dealership (now at 180,280). 2 previous owners, both kept up on oil changes at dealership, and most recommended service scheduled overhauls, albeit 2nd owner let some things slide, which I nearly done fixing. Said previous owner had been getting a P0420 code intermittently for a couple years, which would mostly stay off if high octane gas was used (my attention brought to it after stopping at a crap fill station). The CEL came on, hesitation more noticeable. Since purchasing, the most noticed defects in performance was tendency to hesitate when accelerating, and some lagging while cruising. {Examining service history, found prev owner first attempted to fix code by replacing Catalytic Converter; altho declined anything additional.** Knowing that Cat Converter was relatively new within a year or so, I opted to change O2 Sensors. Front one is cake, back one is tight hand squeeze, downstream sensor connector requires unbolting the driver's seat to get at the wire harness. The plugs for the 2 upstream wire harnesses look slightly different than the one downstream like 2 notches instead of 1 or vice versa...so that won't surprise you. This successfully cleared off P0420 without remission. I cannot say whether the previous owner leaving the O2 sensors un-replaced for 2 years affected the fuel/air ratio that led to further issues, however within a couple months my Lexus, having this issue nipped in the ***, was able to finally identify the source of the biggest performance issue i'd noticed since purchasing.....

blckphillp

1999 ES300. Part 2 of my repairs: generic code P0446. Although p0420 code did not return, and car ran smoother in general, the symptoms since always had continued. Hesitation when trying to accelerate, and surging and lagging while at cruising, sometimes seen as an RPM drop letting off pedal, then surging moments later. CEL appeared again, along with 'TRAC' light just beside it {CEL & TRAC have remained appearing in tandem ever since**; relaying a code for P0446: EVAP Emission System- Vent Control Circuit. Symptoms while noticeable, were not serious, so I let it be for a few weeks while I researched (cheers to Club Lexus Forums). Symptoms turned for worse, especially set off by a day of heavy driving. Culminated in sudden appearance of a rough idle after several fast accelerations, although idle was within car's ability to smooth out after computer readjusted (typically after a minute or two of rough idling). Rough idle would trigger flashing CELight; subsequent OBDii scan showed random misfires in Cylinders 2,4,6...Fortuitously, I happened then to realize/figure out that my once thought generic/universal scanner could be adjusted to include vehicle make and year upon which it returned a Lexus code P1354. As the symptoms still in general could possibly be attributable to a vacuum leak (granted presumably growing). I decided to hold off addressing new code until after attempt to fix 0446, in case it was merely sub-symptomatic. I opted for swapping out Charcoal Vapor Canister, as a consensus of others seemed to have good luck solving the problem specifically with this. Also, it seemed more prudent & less work to exchange the entire Canister {Dorman 911-617** which came with a Vapor Canister Valve aka Vacuum Switch Valve & Pressure Sensor already assembled with...than to try dissect and remove the individual VSV [which is also is a nightmare to find given all the different vacuum valves and part numbers and brand specific item numbers-- (which I have witnessed on several occasions where someone on a forum listed a part number incorrectly (tho likely compatible enough not to notice))] as a cheap half measure. Like anyone, I try to avoid unnecessary expenses, but this worn out component is just as well swapped out entirely when nearly 200k. I walked away spending just at 200$ acquiring part online. Very do-able at home by lifting car rear on ramps or jack stands, and loosening the muffler to make room to slide out old canister. 3 small hose clamps, 1 large hose with SANOH retaining clip connector, 2 plugs, 2 bolts, 2 snap fittings and the better part of an afternoon and voilah! Performance increase with car was dramatic. Results were immediate, car lost all hesitation. For the time being, didn't notice any lagging and lurching. Didn't see any reason to continue debugging vacuum line i.e. purge valve might've been next, but no vacuum type symptoms, and after clearing codes, car drove with better performance than ever. However, I didn't suspect the p1354 was without a separate issue, so.....

blckphillp

1999 ES300 Part 3 of repairs: Lexus code P1354. Presently awaiting Amazon to deliver my Dorman 917-214/917-211 Variable Valve Timing Camshaft Solenoids. Unfortunately I am finding out if you opt for the "free shipping" option for greater amount purchases F%&$^@ing Amazon will actually shelve your post item for a week, since it really only takes the postal servicers about 3 days to go anywhere continental, in order to make you opt for buying the priority, 2 day and 1 day shipping options for the extra fee. It happened with my last car part, and now with this one...so if you need your car part fast, Amazon will mess with you unless you pay them extra. ANYWAY although my aforementioned rough idling took the form of misfires on one bank of the engine (cylinder 2,4,6 side) and that would indicate the VVT oil control valve on that side specifically is causing problems, it is better to opt to do both banks.
After fixing the charcoal canister, and it might be worth mentioning, doing an oil change (with synthetic) it was actually quite a while before the CEL came back on, I first detected p1354 after the rough idle formed while diagnosing P0446 in previous part; Now eliminated as possible symptom of the vacuum leak. .. I went on an extended Test drive on highway after a week of phenomenal performance, which finally brought out the problem again with marked symptoms. Car began stumbling.... like it was shifting into overdrive and back, for about 3-4 seconds at time. It was not unlike the lagging and surging from previously, but now much more serious. CEL + TRAC lit up, still indicated Lexus specific code P1354 {variable valve timing**, which now explained the rough idling and misfires, and exasperating the previous vacuum leak. Clearing code and turning off engine helped get rid of these "hiccups," and on any short drive, doesn't seem to be an issue until the engine has been running for about 25 minutes or so, and begins stumbling. The warmed oil viscosity change may explain that as the Oil Control Valves (aka VVT solenoids) are the root of the problem. My part will arrive tomorrow, and I am hoping that changing them, cleaning oil valve filters, will fix everything once parts arrive. I went through Lexus service history, and was relieved to find out that the oil was always changed with synthetic. I have read that the worst source of slugging comes from conventional oil build-up. However, one of the things that impressed me when i bought the car was how clean the oil looked, and how well the changes were kept up on. It does seem that after 200k miles, a small bit of crap will build up in the oil valve lines, caught in the filters, and the solenoids will plain simply wear out. Some technicians sounded like doomsday criers talking about sludging happening with these models. However, it seems like many people have simply changed their VVT valves and that was that. As I have not got quite that far, I am curious if the Camshaft position sensors or the knock sensors ever are ever part of this issue? Or if they were, would a different code be present? Just trying to foresee anything else I should deal with immediately. I feel fairly good that the problem will be resolved forthwith, but if anyone can comment from experience, please do. I just wish Amazon would hurry the F&^% up. TEN days...can you believe it? what a scam.

mugencivic

Thanks for this post. the first 2 parts/codes is 2 of 4 that i have (the other 2 being both knock sensors). The only concern I have my the p0420 on my 99 ES is that I don't know which one it is. My ES is @ 205K miles and more than likely do need to change out the cat's, but my do both O2 sensors (since it's cheaper) first and go from there.

I have a question about the P0446 code. Did you gas thank/cap hold pressure when that code was showing? I've replaced my gas cap with a new one and it still doesn't hold pressure. I've also read that the gasket for the neck wear out and have to be changed and the gas tank/cap holds pressure after that fix.- Thanks

blckphillp

I have driven around for a couple hundred miles, and have noticed no symptoms further as reported, and all CEL/Trac lights (1354) have stayed off, after having done replacement of Variable Valve Timing Camshaft Solenoids on both banks. repair went smoothly...found ii didn't even have to remove air filter or detach any hoses to finagle them in and out. They are just barely short enough that they can squeeze out...provided you have dexterous enough hands to reach through all the chaos and detach the plugs. having tool options helped immensely- a 6in socket extension and a short socket for the 10mm nuts, also if i didn't have a magnet wand, I would have lost a nut somewhere in the block hopelessly.. I ran out of time to see to the filters, but it seemed that doing both of these would require work to provide access...although the bank 2 (front) filter is way more exposed/accessible, and as I was primarily getting misfires on bank 2, i may settle on cleaning just this one. Either way, code 1354 has remained off and car is performing best it ever has.


>>a question about the P0446 code. Did you gas thank/cap hold pressure when that code was showing? I've replaced my gas cap with a new one and it still doesn't hold pressure. I've also read that the gasket for the neck wear out and have to be changed and the gas tank/cap holds pressure after that fix.- Thanks

It is a rare and unlikely/lucky source of the leak to be merely from the gas cap. if you are specifically testing the pressure of the gas tank, and finding it loses pressure after eliminating gas cap possibility, that would be a further indication of the charcoal vapor canister, it would seem to me, as it is the next thing circulating with the gas tank, and Canister inclvdes a Vacuum Switch which releases directly to atmosphere. Component definitely likely to have burned out by your range of miles. Also swapping the canister includes a pressure sensor, which may be the problem. Keep in mind that 0446 is an EVAP vapor control CIRCUIT failure, so replacing the vapor canister with its two major valve solenoids that plug in...is the reason that code specifically gets resolved 9/10 times with this part...having read many dozens of posts from people in same situation.

mugencivic

Awesome, thanks for that. It makes total sense on why its not holding pressure. So i'll be adding that to my "must replace list".
I tell my car buddies that my car is a good example of what happens in the long run when you use cheap gas and not the proper octane with the emissions CEL codes it has lol

blckphillp

[QUOTE=mugencivic;9630808]Thanks for this post. the first 2 parts/codes is 2 of 4 that i have (the other 2 being both knock sensors). The only concern I have my the p0420 on my 99 ES is that I don't know which one it is. My ES is @ 205K miles and more than likely do need to change out the cat's, but my do both O2 sensors (since it's cheaper) first and go from there.

i may just be reading into the word both as 2, but it sounds like you are planning on doing just 2 o2 sensors...You should do all3 O2 sensors, seriously, at 200k miles, there's no way that they don't all need it... one of the ways the o2 sensors work is by measuring the difference between the upstream and downstream sensors' readings. hence, you want the sensors to be on the same baseline, so the results are more accurate, and it can more realistically tell you if the catalytic converter is in good condition, and not further acceleratedly wearing out the cat conv because it is compensating for inaccurate worn out o2 sensor readings... by all means, do the o2 sensors first, you may not need to do cat conv for some time, and new sensors will help pinpoint the other problems. I did denso 234-9007,9009 sensors on the upstream because they are manufactured specifically for front and rear upstreams which are asymmetrical, and hence should have slightly different readings ergo better to have assym sensors not dual same universal upstream sensors.. if memory serves i may have got bosch downstream as it was what the shop had avail, and it was not universal, but specifically compatible. I don't trust the universal sensors. I want replacements as specific to the original as possible...without forking over the money to buy expensive lexus brand.
i haven't dealt with knock sensors before. keep us informed what happens. I wouldn't be surprised if your computer doesn't pinpoint a more precise problem once the 420 and 446 are dealt with.

mugencivic

thanks for that explanation, I think I'll start with the o2 sensors and hopefully fixes that CEL issue. but I've been noticing that OE brand sensors are a must for the 3ES to insure accuracy. since the o2 sensors are the cheapest parts of all my issues, that will be the first issue to address lol

yeskay

hello Phillip:
my es gets p0420 error. i thought it was the cat convertor. you never got o2 sensor errors?

blckphillp

in my case, I was fortunate enough to have both the carfax report and the Lexus dealership service history, so I found out that the previous owner had already been getting the p0420 code for the last two years, and indeed, yes, they attempted to fix it by replacing the Catalytic Convertor when the code first appeared. After that, they would still get the CEL to pop on and off...and generally, as long as premium grade gas was used, it stayed off. When I received the car, I had no CEL for about 3 months and then the light popped on with 0420 after putting regular grade from a crap station, and as was typical, it turned off by itself after refilling with premium and driving around a week or two. I opted to presume that since the Cat Convertor had recently been replaced, the problem lay with the O2 sensors since they HAD NOT ever been replaced, and are what informs the computer how the Cat Con is performing. At 175,000 miles, I figured the O2 sensors were shot, and I was correct... 5000 miles later, I have not had any continued problems with p0420. to answer your question, no, I did not receive any other codes more specifically flagging the O2 sensors... had to deduce problem given car's history and others' results and basic knowledge of the parts involved

blckphillp

So its been more than half a year and a more than a few thousand miles since the last of my home repairs, and I am happy to report no instances of CEL returning, and 95% symptoms remission.
To summarize, my past ongoing incursion of CEL+TRAC lights diagnosed by OBD2 as codes P0420, P0446, P1354 for implicit errors as described in previous thread posts,
were successfully addressed and relieved by replacement of the following parts. Impairments may have arose in tandem/have ongoing roots to other problems unidentified or not yet manifested (hence question mark).
P0420. . . (+?)
Denso 234-9007 Upstream Rear Air Fuel Sensor (Bank 1 s1)
Denso 234-9009 Upstream Front Air Fuel Sensor (Bank 2 s1)
Denso 234-4137 Downstream Heated O2 Sensor (Bank 1 s2) <> Bosch 13353 O2 Sensor (second choice)
P0446. . . (+?)
Dorman 911-617 Vapor Canister with Valves
P1354. . . (+?)
Dorman 917-214 Variable Valve Timing Solenoid/Camshaft Oil Control Valve right
Dorman 917-211 Variable Valve Timing Solenoid/Camshaft Oil Control Valve left
(prices on rock auto in order: 120+120+50 +191 +37+38 =@500$)

Since then, when I executed my (first since owning) oil change, I learned that Lexus ES300 needs a FULLY synthetic oil to prevent sludging. Previous changes at the dealership by previous owners used 0w-20 (which is
what they have on hand to use in the newest models) which is good for 10k miles. However, I returned my ES300 to its specified 5w-30 full synth, good for 5k miles(?) I'm either going with Penn Plat, or Valvoline.
I couldn't find new Oil control Valve Filters then, but next oil change I am planning on removing, cleaning and replacing oil control valve filters to better fix last problem of P1354 VVT system malfunction.
The vehicle really is meant to run on the higher octane gas, and I do see better performance when i fill up with premium instead of mid-grade...and less little occasional hiccups of my prior symptoms
(like seeing the rpms dip noticeably when taking foot off accelerator while cruising at slow to moderate speed--e.g. lagging--but then they go back up). All in all though, problem symptom traces barely experienced.
other than an oil change the biggest fix i've had to do was replacing wiper blades

since my last post I did recieve a question which i didn't reply to since I had didn't have any answer information that wasn't already earlier in the thread
Dealer is stupid. Even rock auto mentions that those sensors should be replaced in pairs, both ups/both downs....I think all at once.
Regardless of sensors being the new A/F or traditional O2 tech, they all wear out the same, so in a high mileage period of part life expectancy being reached (about +/- 125K miles), its still good to replace all of them at once. Otherwise, you are taking for granted many assumptions: 1.)that the ECM correctly identified the ONLY problem sensor 2.) Your diagram/info source identifying which side of the engine Bank 1 is on was completely reliable/clear (I would bet money that countless lay/home repairs either did the right part in the wrong side of the engine or the wrong part in the correct side, etc) 3.) that the other sensors won't burn out soon enough that you could have saved yourself trouble fixing them all at once or 4.) the fuel mixture's adjustment based on now imbalanced sensor readings won't damage the cat converter, creating an even more difficult and expensive repair than it would have been just to have done the freaking sensors! So people, stop dragging your feet, and cutting corners...do yourself a favor and replace all of those high mileage nearly burnt out sensors at the same time...which will provide you with a last even better reason: Peace of mind--the simple reward of confident relief, no lingering doubt, and even if a CEL comes back on, you can hone in and move on to the NEXT issue.

I know it is confusing trying to find and decide on a part number, so here is my approach to zeroing on the best replacement part:
When I choose a brand/part number to purchase for any component, my process typically involves consulting several different retailer catalogues and several different engine/chasis diagrams for as close to my model as I can find (with part numbers listed/labeled), and comparing any discrepancies and multiple results to figure out which parts are closest in specifications/engineered most precisely for a particular vehicle, and which options popped up as fitting a generic universal set of vehicles...or came up due to differences in part naming (I experienced a lot of this looking for my oil control valves AKA variable valve timing solenoids AKA 3 other terms). I want to identify when a part contains other parts that won't be necessary to buy/easier to fix in tandem (as was the case in choosing the dorman vaccuum canister which contains valves and solenoids that are listed separately superfluously). I also want to find which part has the best price at which retailer. I'm not spending the kind of cash to buy a part from a Lexus distributor. My goal is getting something that makes it worth fixing a USED car, but with a fix that lives up to being called a fix. I do consult forums to see what others used...but I never assume someone else's part number is correct (Many times they have one meant for a different car year, or a different engine type for a congruent vehicle make/year...) I spend many hours learning about the different components whenever I am faced with a new error i've never dealt with before, and I'm always elated to fix something myself without a mechanic or dealer.
To illustrate my part choosing logic in process take how I selected my o2 sensors:
For the o2 sensors upstream, I desired specificity between Bank 1 and Bank 2, and designated as Air Fuel Sensors, the newer tech of o2 sensors with the least carbon emission. Denso is only brand that differentiates the sensors 234-9007& 9009, and is the OEM for that part. Whether the front and rear bank upstream sensors are calibrated differently, i don't know, but it is nice knowing they are if they need to be. If nothing else, the wiring is proper length. Bosch and other brands' upstream AF sensors weren't differentiated- just 2 of the same part number. Then there are even cheaper "Universal Oxygen Sensors" (denso 234-4209 & others), which are "universal" (term makes me cringe) and non AFR (older technology). Just the thing [yeskay] would want to avoid in California. One person earlier in this thread attested that only OEM equivalent sensors seem to function properly on this car. Those would be the Densos 234-9007/9009. As for downstream...
According to diagrams and charts i've found for Lexus ES3 and other models and nearby years, Banks 1&2-Sensor 1s all call for "Air Fuel Ratio Sensors," yet Sensor 2s typically get labeled as "Heated Oxygen Sensors." Indeed, the downstream component is a bit different: wider and shorter cylinder& plug/wire harness notches are different (B1S1/B2S1= [0-flat,1,2,3]), B1S2= [0-flat,2wide,2,2]). Denso would be the first logical choice, as it's the part oem and matches what i used for upstream. The Direct Fit Denso 234-4137 Oxygen Sensor (heated) is the best choice to consider. However since it wasn't in stock so I got The Bosch 13353 Engineered Oxygen Sensor (heated). I think on the downstream ones, i won't see any bugs for going with another quality brand, being heated O2 rather than AFR, the tolerances are not as tight, there is only one downstream sensor so no complement to have to match it up to...In fact several of the brands for the downstream sensors are all about the same price and probably comparable in quality.
The parts i take out look exactly like the parts i purchased, so I proceed. Parts installed, I reset the ECM, drive the car, performance improves, one less code appears, success is inferred. Proceed to next problem.