vaskinfan

In 2013 I bought a used ES300. For the past couple months I have had my car at the mechanic because my check engine/trak off warning lights are on.
On 2/20/17 @ 177734 miles I took the car in to get the timing belt changed and to check error light codes. Was told both up stream 02 sensors needed changed.
on 4/10/17 @ 178367 miles I had that done.
a couple weeks later same warning lights came on, took it in on 5/17 and mechanic stated I have an aftermarket gas cap, and suggested try a Lexus cap before we did anything else.
couple weeks later, light on again, took it in on 6/2 was told I needed to have "evap cannister" changed. Asked mechanic when he called if he was sure this was the problem. He told me he "knew" this was the problem and I agreed to have that changed.
Within a week and it is on again.I am taking it back to the mechanic this week. I certainly don't claim to be a mechanic, so does anyone here have any ideas on what may be going on.I can't afford to keep having all these repairs done. all have the above visits have cost me approx 2300. (There was an oil change mixed in with one of the repairs. does it hurt the car if I choose to ignore what he says next ? Or, is there a certain repair suggested I should not ignore.

Thanks in advance for any advice and/or suggestions

1960vw

First of all, welcome! Second , you need to buy your own code reader, not an expensive one. Around 30 dollars would be just fine. Harbor Freight has some decent ones. It plugs inside the car underneath the steering wheel. Once plugged in , turn car to on, not running, but just on where the dash lights come on. Go through the procedure on your scanner and viola! VERY EASY !! That way you can pull your own codes and get on this board and find out the true issues. We can't help you without the codes! Mechanics will bounce you around at times just for the money or they don't know about Lexus's.. Here, the advice is free and usually you could solve the problems yourself and that's cheap.

nsghtbrwry

Sounds like your mechanic is just throwing parts at the problem. I'd find a new mechanic.

So you've had the gas cap and canister replaced, I bet it cost you a pretty penny. Things left are all the EVAP hoses and the two solenoids. I suggest testing the two solenoids; one is mounted to the rail under the engine beauty cover, and the other is mounted to the EVAP canister near the fuel tank. For the hoses, a smoke test will find a broken one.

vaskinfan

And I've had both O2 sensors replaced, and yes, all of this has cost a pretty penny !

raven316

Ugh. I bought my 2006 Es 300 from a buddy who had it serviced regularly. Like a dumb** I took him at his word and bought it without doing a buyers check. Fast forward past a timing belt, plugs, oil leak fix and new tires and the damn CEL keeps coming on. My mechanic is usually very good but he says he's not getting any code and is stumped. I've pretty much had it with this car but I worry about trying to sell it with the CEL on!

1960vw

Raven, take vehicle to place like Pep Boys, AutoZone or the like that run free code checks. Another set of eyes could be some help. If you get codes, put it in search box to get answers.

raven316

I took your advice and got
PO174
PO171
PO430

Guess it's the cat.

1960vw

Yes and clean your MAF (Mass Air Flow) Sensor.

vaskinfan

OK, I bought a code reader, and the only code that came up was
> PO446 *10 (not sure if you needed the 10)
evaporative emission system vent control system

This code came up on both the "stored" and "Pending" codes

Any ideas ? How much is this repair ? Is it needed ?

Thanks

yeskay

i had the same code. it was the evap canister. part cost $200 via amazon. do a engine diag via dealer to confirm if this is needed.

1960vw

Ok what happened to the other codes? Did the shop clear them? Since you have a new canister, I would suspect some major vacuum leaks. Check all hoses in engine bay. Especially thin ones on top of manifold. Make sure they are on snug and not cracked. Then check make sure big hose under air filter/ cleaner box is firmly attached. Check hoses by fuel filler are tight. Follow them to canister and re-tighten if necessary. Other than simple stuff like that It probably has to go to the shop. I don't get a warm fuzzy feeling for that mechanic of yours. Find a shop that does a smoke check. Here in Cali it's $75 Everything is more here so it should be less there. Smoke machine finds any leak in vacuum system and if simple they should be able to fix it cheaply.

vaskinfan

I have no idea about the old codes,unless they don't show up on the $35 reader I bought. Also, bought a bottle of Cataclean, thinking code may come up as a CAT problem. Still thinking of using, what's everyone's opinion on this product ?

nsghtbrwry

Troubleshooting EVAP is very tedious if you do it properly. Lot of potential failure points for something that offers very little benefit, and I'm saying this as a tree-hugging Californian. A few things to knock it down, as I've successfully dealt with several 1MZ EVAP systems:

- there are two VSV's/solenoids: one on the rail under the engine beauty cover, and another mounted to the canister near the car. Most of the time, it's a failure of the rail VSV, but both should be tested. This is the easiest thing to check.
- hoses degrade, especially on cars this old. My local shop charges $80 and takes about three hours to smoke the system at two points: through a hose attached to the canister (rear), and another at the rail (front). Pretty surefire way to find busted hoses.
- I'd go to the canister last. First, aftermarket canisters vary wildly in quality (although they're half the price of OEM) and I've read reports of them failing within months. Some people refill the old canister with aquarium charcoal, but this requires cutting it open and making sure nothing is clogged with old charcoal.

There's a guy on Toyota Nation who got rid of his P0420 by running a couple bottles of Cataclean through. I'd say that means it works, but it's a crapshoot; it only works if the cat is actually dirty, and not degraded. Read the ingredients, it's just a strong solvent cocktail. Also realize that since it goes in through your fuel tank, you should worry about it stripping lubrication from your cylinders.

yeskay

since the evap canister is replaced by the previous tech you should take the car back to him. was it oem canister. or used / aftermarket.