uncledave11

Hi Marty: I appreciate the response and yes it does sound like coil packs but.....since one of them I had to replace about 2 months ago is new, the misfire codes are all in the front bank (cyls. 2, 4, & 6) what's the reason for your conclusion? Coil packs are about $70 each, normal preventive maintenance for electronics is that if you have alike components in a group that perform the same functions you can expect additional failures to occur after the first incident. Yup, 19 years and one finally fails and I know the possibility of others to follow exists. but at the same time I'm trying to avoid "breaking the bank" while not being a cheapskate due to recent finances that we won't discuss here. I'm still looking for a more scientific explanation using the laws of cause and effect! what started with a vehicle that needed a good tune up and ran ok and all 6 cyl without any issues that suggested serious problems. Yes the plugs were quite worn and the air filter was dirty. The only codes I had was the one that gives owners a fit and cost large $ to eliminate is the "catalyst is below spec limits" Meaning your converter doesn't quite get as hot as it is supposed to and because of ECU parameters that can't be bypassed or changed you get a anti lock and trac off signal that has absolutely nothing to do with the emissions end of anything! But it will get (especially moms!) your attention when you feel unsafe in winter driving conditions. Your anti lock brakes of course still function but your traction control does not. But the Lexus dealer service dept will fix it even if they have to replace the entire anti lock brake control system and every other sensor related to emissions except the cat converter. Having bought this car in 2004 as a pre-certified car with a 3 yr bumper to bumper (20.000 miles at delivery) I saw every failure incident get parts thrown at it till you wondered how can they afford to operate that way? Ha, 14 yrs later, I know. So If you or any other members can come up with any other possibilities I'd be all ears an eternally grateful! Thanks, Dave

After a tune up, R&R spark plugs, air filter, cleaned MAP sensor, coolant hose fix, PCV valve cleaned...everything went extremely well. While getting a very smooth running engine up to operating temp to check for any leaks (ran AC on full, then heater to make sure coolant levels were full and engine at normal temp) the engine went from smooth idle to surging slightly RPM up and down and running a bit rough. Check engine Light flashed so checked codes and found random misfire and a code for cylinders 2, 4 & 6. (front bank) Checked all vacuum connections, electrical & anything else I might Have disturbed during the tune up. I'm guessing there is something now going on that is affecting only the front cylinder bank but I'm not sure where to look as the back bank (1,3,& 5) seem to be fine (no codes anyway!) Any incite on what to run down first as I feel there has been a change in fuel mix due to a vacuum leak maybe to the front bank? Appreciate any response or suggestions on where to proceed next! Thx, Dave

OUTSIDE temp sensor can also cause confusion

It might be a good idea to check Cat converter for restriction. it can cause similiar codes to trigger.

Hello to all...here's an update to the final fix. I watched the front (radiator side) A\F sensor voltage and noticed after a while on the highway is got pretty unresponsive compared to the rear one. So...Being it was the original I replaced it with a Bosch 15217 wide band sensor. My local parts store beat everyone else's price ($155 out the door), so I swapped it out, cleared the ECM and proceeded to drive and see the results. The engine ran beautifully for about 40 miles with repeated stops, cycling the ignition to add as many start up cycles as i could. Al well well until suddenly the trac light pops on and about 30 sec. later goes off. Then about 2 minutes later the engine jerked while running about 30 mph and rolling up to a stop sign, began it's same old trait of idling badly. No check lights came on and I returned to my garage. Reading the codes now showed a P1354 (Valve timeing circuit) error so I'd have to wait for the new OCV's to come from Rock Auto. This past monday I swapped out the new valves and noticed one charactoristic of the piston movment on the front valve i was replacing. Compared to the new valves this one had a slight "friction snag" feel to it as I gently pushed on it to open it against the return spring. I'm confident now that even though a valve checks good for ohms and actuation with a 12 vdc source, It may bind just enough to cause the valve timing to be "out of sync", so to speak, with the rear camshaft! This would explain why the engine would run great for a while until the parameters learned triggered a failure and could not correct it due to the ocv sticking at various positions! Hope this helps others!

make sure your engine is getting up to normal operating temp (at least 170 deg F.) If your thermostat is old it may be stuck open causing overcooling.

P1410 is an EGR circuit\valve problem:your EGR valve needs to be cleaned if possible or replaced if necessary. Try cleaning first

The vapor pressure sensor and VSV for vapor pressure sensor are used to detect abnormalities in the evaporative emission control system. The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal. DTCs P0441 and P0446 are recorded by the ECM when evaporative emissions leak from the components within the dotted line in fig. 1, or when there is a malfunction in either the VSV for EVAP, the VSV for vapor pressure sensor, or in the vapor pressure sensor itself.

Well, I didn't see any replies for a fix so I continued to search the blogs and any other info on way could be going on here....and...I found the solution! This might be of value to other ES300 owners that have spent time & money in only to have the problem re-appear! I've learned a great deal about VVT in relation to air fuel sensors and how criticle the oil control valve must operate to keep the engine performance at optimal. The ocv's are really quite simple in operation but are very, very precision in construction. Time and ware will take it's toll on these no matter what oil you use or how well you keep up the preventive maintenance on your engine. They will operate with less and less efficiency util the day comes when you suddeny notice your engine running rough and throwing multiple codes that lead you and your mechanic on a merry chase. I revisited the culpret after several removals, cleaning and testing like the manuals say. However, it wasn't time I took the valve out and put it on my variable DC power supply, that I truly was able to observe it's operation! In the process of "ramping" up the voltage to move the slide inside the valve, I felt slight notchy movement instead of a smooth progression. You can't feel this when using a small screwdriver to move the piston to check for sticking even after cleaning! After repeated cleanings with solvent with the valve held open, I now noticed a smoother but not perfect progeressive movement from 0-7 volts DC applied. After reinstalling the valve and clearing the ECM no codes have been set after 30 miles of driving! Still, I ordered 2 new ones from Rock Auto due to the fact that these are still worn and I need to restore precise control to the VVT circuit if I want the engine to perform to it's maximum efficency. Hope this help's anyone out there that is as frustrated as I was!

Hello to everyone. got a real stumper i've been after. Recently had my 99 ES300 start running really rough (very sudden) Now after going though all the sensors, cleaning out the VVT actuators and testing of course, cleaning the VVt oil filters, removing the Idle air control and cleaning (that was sticking some), cleaning out the throttle bodies nicely....whew. now it runs and idles 99% better with just a touch of hesitation off the line. You can floor it and it goes like a scalded cat to 100! My big concern. I feel a tiny bit of mis fire (no codes) sometimes at 40-50 mph and then gone. The code reader in live mode show all the O2 sensors working within there voltage ranges but... the STFT for Bank 1 sensor 2 reads 99.2% all the time. The other two are making trim corrections but this one keeps reading 99.2% . Anyone got a clue whats going on here? Both upsteam O2 sensors were replaced about 8k ago. Help! I've reposted this as I've been really trying to nail this down. I randomly get codes such as the normal random misfire on 2,4,6 with a P1354 (cam timing fault, have replace belt and all in good order there) and some time a P1150 front (radiator side) A\F sensor. Help!! Thx uncledave11

Hello to everyone. got a real stumper i've been after. Recently had my 99 ES300 start running really rough (very sudden) Now after going though all the sensors, cleaning out the VVT actuators and testing of course, cleaning the VVt oil filters, removing the Idle air control and cleaning (that was sticking some), cleaning out the throttle bodies nicely....whew. now it runs and idles 99% better with just a touch of hesitation off the line. You can floor it and it goes like a scalded cat to 100! My big concern. I feel a tiny bit of mis fire (no codes) sometimes at 40-50 mph and then gone. The code reader in live mode show all the O2 sensors working within there voltage ranges but... the STFT for Bank 1 sensor 2 reads 99.2% all the time. The other two are making trim corrections but this one keeps reading 99.2% . Anyone got a clue whats going on here? Both upsteam O2 sensors were replaced about 8k ago. Help! thanks,

looking for info on replacing all the bushings on the rear suspention arms. (rear two adjustable, front two fixed). Have found a "kit" from whiteline, P\n W61446. Anyone had experience with these replacements? Hate to get wrong parts and find out during teardown there not the right ones! Thanks, Dave

Hi: New to forum. Have 99 ES300 bought in 05 w\ 20K, now at 109K, Handling getting vage, not sure footed as used to be. Wanders a bit but doesn't pull right of left. Would like help on where to look first? Also, air bag light came on a few days after replacing AC compressor. Had batt. disconnected for several hours. Any tips on what kind of error may have caused? Once in a while the air bag light goes off normally after a startup. Could connector have poor conductivity somewhere? Thx, Dave