AmanES300

Hi guys, new here.

I just purchased a used '01 ES300 w/ 145K miles. I knew it needed some work, but I was (and am), willing to put the work in to learn the car and get it to operating condition. Turns out, I may have bit off more than I can chew.

Anyway, the day after I purchased it, I noticed a rough idle (only happens once the car warms up), so rough that the engine stalled. At the same time, the old battery finally gave out. The seller had a new one sitting in the trunk so I replaced that immediately and got the car started again. I had to keep it in neutral when stopped to keep the RPMs from going too low and stalling. I thought it was the old fuel in the tank (the car had been sitting for about a year) and put some fuel stabilizer in the tank, which seemed to help the car from dropping RPMs so low as to stall, but the rough idle was still there (really rough, the hood was visibly shaking). When I finally got an OBD scanner, the only code I was able to see was P0103 (MAF circuit High), so I checked the harness was seated properly, and cleaned the sensor with MAF cleaner. The car seemed to work almost perfectly after that although I did not take it out for a test drive (I let the car warm up which is when the idle usually becomes rough and it stayed running smooth).

Turns out, the cleaned MAF has now revealed a host of problems with the engine. After getting home from work, I took the car out to test drive and check that the rough idle was gone, I parked the car back up almost immediately as the RPMs began dropping incredibly low after about 2 minutes. The brake pedal was also hard when the RPMs were below 1K. I checked the engine bay and could hear an air leak which was coming from the air intake. I looked closer and see the intake tubing between the throttle body and whatever is after the MAF was loose. After attempting to secure it onto the plastic chamber after the MAF, it simply tore off. It was hard as a rock and was probably dry rotted. I checked the DTC's again and got a bunch of them:

P1349 Fuel Level Sensor B Circuit High
P1354 Ignition Coil C primary Circuit malfunction
P0300 Misfire Detected
P0301 Misfire Cyl. 1
P0302 Misfire Cyl. 2
P0303 Misfire Cyl. 3
P0304 Misfire Cyl. 4
P0305 Misfire Cyl. 5
P0306 Misfire Cyl. 6
P1150 Lack of HO2S21 Switch - Adaptive fuel at limit.

I've ordered replacement tubing for the throttle body and 6 spark plugs.

Also, turns out the Check Engine light doesn't work at all. I believe the seller disabled it, but that's on me, I should've checked.

Any idea what could be causing misfire on all cylinders? Any tips for a newbie? Thanks in advance.

SOLUTION: Replaced both Oil Control Valves as they both were bad. One not working gave bank 2 cylinders misfires, but since both were bad for me, it gave both banks misfires.

LeX2K

First thing to do is get the intake tube replaced, clear the codes and go for a drive.

AmanES300

Alright I replaced the hoses and AOTA running great. No more rough idle and the throttle is quick to respond. The only code I have left is P1349 which is VVT System Malfunction. This time I’m using Blue Driver as my scanner so the description is different from the list device i used where I got the same code along with all the misfires. I’m getting the oil changed right now so hopefully it clears it up. Anything I should be aware of relating to the code? Anything I should do to check it out?

LexusB5

There is a filter for the OCV's located directly below the solenoid's them self. Remove the 14mm cap bolt and there will be a small cylindrical filter about 1 1/2" inches long. Carb cleaner or Brake Parts cleaner will work. Very important to keep clean oil in VVTi engines, don't add any additives to the motor oil either as they can cause sludge to break free and clog the filters again.

AmanES300

Damn. I allowed the mechanic to use engine detergent. Hopefully it doesn’t loosen up too much sludge. For the OCV, how would I access the filter? I can’t seem to find any videos for the 1mzfe doing that. Also getting a P1354 code for bank 2 which I assume is the same issue with either the OCV or filter.

LeX2K

Should be able to figure out by looking at this thread
https://www.clublexus.com/forums/rx-...ement-diy.html

AmanES300

Okay as I was driving to get new tires, the rough idle and low rpms came back. I checked the scanner and all cylinders have misfired again. I opened the hood this time while this was happening and the exhaust manifold from bank 2 was red hot and smoking a little from the heat. I’m not sure what to do at this point. Bad catalytic converter?

LeX2K

Cat glowing read is usually caused by too much fuel. I've yet to see a cat glow red when it was clogged but I've read about people claiming this happened. The first code you listed is a VVTi fault code

AmanES300

I managed to clean the bank 2 OCV today and checked on the 2,4,6 spark plugs. The bank1 OCV and filters will need to be done another day.

The spark plugs I checked were all black as expected since it’s been running rich and and the ignition coils were covered in oil. It’s only done it once before but there was some smoke coming out of the exhaust and it was slightly blue

Also, it runs fine when the codes are cleared, but once whatever is causing the rough idle causes it again, more misfire codes.


oh and STFT is always zero when the issue shows up.

AmanES300

Okay I did some more research and I’m thinking it’s the fuel injectors. Since the issue only ever shows up when the engine is at operating temperature, it’s gotta be affected by heat. Fuel injectors fit into that. Since the car runs perfectly otherwise, spark plugs and ignitions are good, as well as exhaust (no manifold glowing red during my test drive after replacing intake hoses). Cats should also be good since I haven’t gotten codes for those.

Bad injectors would explain the temperature relationship and the STFT not working on the obd2 when the issue occurs. It also fits into the symptoms I’ve been having (fuel smell coming through AC sometimes, engine running rich, guzzling a ****ton of fuel, and stalling and bucking under different engine loads). I’m going to test the injectors and computer when it’s idling great and then drive until the issue shows up again and test them after that. Only one question; where can I test the driver that controls the injectors? I want to test it at the driver output, so before it even gets to the harness. Thank you.

HomerJay

It's seems unlikely all the fuel injectors failed. Did you replace the spark plugs after inspecting them? Also, recheck your recent work for disconnected and/or cracked vacuum lines including electrical connections.

AmanES300

I replaced the bank 2 plugs after inspecting them with denso OEM ones. The ones I pulled were NGK. I’m going to pull and replace the bank 1 plugs today after work. I’ll also check all the lines today. I read somewhere that a shorting fuel injectors would cause excess fuel in all cylinders for that bank but I don’t think that’s right. Worth a try though.

AmanES300

Okay I’m not sure why it didn’t occur to me until now but the issue has been staring me in the face this whole time and I’ve been ignoring it. It’s the Oil Control Valves. I’ve had the codes for it since even before I fixed the air intake hoses.

Gonna write the explanation out so you guys can tell me if I’m wrong.

The reason ALL cylinders would misfire is because each OCV controls 1 bank. If one is bad, that’s half the cylinders misfiring already. In my case, I’ve got codes for both, so all are misfiring. That would also explain the tons of fuel it’s guzzling which would then explain the red hot exhaust manifold. It also fits into the temp variable as it’s a solenoid (higher temperature coefficient when they go bad -> higher resistance -> improper functioning).

I've ordered Dorman replacements (917-211 and 917-214) and will replace them and the last 3 spark plugs today, as well as clean the OCV filters. I will update on the fix if it works and will update original post so others can know the solution if they face a similar problem.

AmanES300

Alright, I replaced both OCVs yesterday and gave it a good test drive and it not having any issues so far. I checked for codes and nothing. Looks like the issue is fixed but I’ll need to drive it for about a week to make sure it’s good. Thank you so much for your help guys, I really appreciate it.

btw, do you guys have any tire/wheel recommendations? Gotta get the dry rotted tires replaced soon so that’s my next job.

80es300

For Tires: I have a 98 es300 and had michelin primacy before (Costco) and they are very good. Recently, I put Defender T+H (didn't want to spend much because the car is old) and they are good too. I like costco for their warranty and they sometimes run $70 off plus free installation.