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2002 Lexus LS430: 000 miles..the check engine light came on

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I have a 2002 Lexus LS430 with 110,000 miles. About one month ago the check engine light came on. The following codes appeared when I connected my notebook to it:
P0300, P0301, P0303, P0305, P0307, P0135, P1346, P1349, P1351

I first replaced both oxygen sensors and cleared the codes. About 3 days later the codes reappeared. This time my wife complained about the engine running rough. I ordered a Lexus shop manual and check the codes again. Toyota says to replace the timing belt at 90,000 miles and this one was never replaced. I ordered the timing belt kit which includes the water pump and idler pullys. I replaced the timing belt and cleared the codes. The exact codes returned. I then checked the timing belt to make sure it was on correct. The timing belt is correct. I then read online about a possible problem with the OCV valves. I removed them and cleaned them. They were not dirty. The motor has no sludge in it. Any idea what it could be? Please don't tell me the timing belt is off because its not. The engine run great when its cold or not under load.
Welcome to just I'm here to help you and your 100% satisfaction is my goal.Here's a quick test for you do on the control valve, Check the vehicle for correct cam timing, make sure that the timing belt was not replaced with a cheap timing belt. If the timing is slightly out of range it can set this code. We have seen certain types of timing belts cause this code.Clear the codes and recheck, to see when the code sets. If the code sets at idle, check the timing belt. If the code sets after the engine has been revved up high, check the camshaft timing oil control valve filter in the cylinder head.
Check the camshaft timing oil control valve. With the vehicle at idle supply power and ground to the camshaft timing oil control valve, the engine should run rough or stall.
Customer: replied 6 years ago.

Ok I've done the test. I tested the control valve first by disconnecting the connector and applying 12 volts to the valve. When I did the engine began to run very rough; when I removed the 12 volts the engine returned to a nice even idle.


Second test: I cleared all the codes and let the engine idle at least 15 minutes; no codes returned. I then reveved the engine to 2500 rpms for about 5 minutes: no codes came up. The engine runs perfect. I remember the last time I cleared the codes we had to drive about 5 miles before they returned. Do you have any more ideas or test?

Checked the wires at the control valve and the connector, see if there's any broken wires where they go into the connector or if any of the terminals are loose or damaged
Customer: replied 6 years ago.
I have checked the wiring and the connector. No problem found. However, this may lead to something; one of the codes I receive is an open oxygen heater circuit. I've changed both sensors and still get the code. Is there a j-box, common connector, or problem area with the LS430 that may lead to a intermitten open circuit? I will trace the oxygen sensor cable; that may lead to something.
Which 02 sensor what is the exact numeric code you're getting
Customer: replied 6 years ago.

The code number I am receiving, among others, is P0135 - Sensor Heater Circuit Malfunction Bank 1, Sensor 1. I replaced both O2 sensors and put my notebook on it and the fuel ratio is excellent. The O2 sensors are working good.


My wife and I used the car this afternoon and it run perfect for about 30 minutes. We drove in the drive way and it started misfiring. It is as bad as when I test the OCV valve and put the 12v on the circuit. I turned the car off and restarted it and the motor misfired for about 15 seconds and then reveved up and then run fine. Can the OCV valve stick?

First I would try another sensor and use a different manufacture because some of them are just not that higher quality if that does not work then checked to see if that there is a broken wire at the connector going too the sensor At the oxygen sensor check to see if there is battery voltage to the sensor on one wire with the sensor disconnected. Reconnect the sensor. With the key on there should be two wires with battery voltage. Start the engine. Check to see if the wire becomes grounded with the engine running.
Customer: replied 6 years ago.
I'll work on the car again this weekend. Please give me some time to do the test. I'll get back to you.
ok let me know what you find thank you
Customer: replied 6 years ago.
My wife an I took the car out and it started misfiring really bad at idle. I opened the hood and took the wire of the OCV valve. Nothing changed. I taped on the valve with a screwdriver and I heard the valve close. The engine reved up and stopped missing. I replaced the valve today and cleared the codes.
sounds good let me know if you need more info
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