I figured the codes out and it turned out to be the oxygen sensors and the catalytic converter, the lights came on a little after 100,000 miles.. typically thats around the time a catalytic converter should START to go out? now roughly around 112,000 miles i noticed some problems with my transmission jerking and my engine reving at waayyyy to high of RPMs, so its a new problem i have to figure out.. can anyone help?
I took mine to the dealer to find out why the VSC, Trac off, and check engine lights are on. They said it is the camshaft position sensor, it retards the timing, and causes it to lose power when climbing. Also, 1 of every 30 to 50 scions have this problem. Sounds like it should be recalled for this. The cost of replacement is about $500 bucks. Get your dry belts and valve cover gaskets changed at the same time to avoid labor charges later. I couldn't believe the dealer charges $89 bucks an hour for labor these days, Rediculous. At least it comes with a a 12 month unlimited mileage warrenty.
I disconnected the battery to reset the ECU. I reconnected the battery, started the car, no warning lights. I drove for 15 minutes and the warning lights came back on. I read wojodr's post, above, added some brake fluid, reset the ECU, and went for another drive. I drove for more than a half hour and no warning lights. Brake fluid, for sure.
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A p0420 sets after Engine and catalyst are warmed up, vehicle driven within set vehicle engine speed range and waveforms of heated O2 sensors bank 1 sensor 1 and bank 1 sensor 2 have the same amplitude. Catalytic convertor and O2 sensors need to be tested
when ever the check engine light is turned on for any reason the vsc and trac light also comes on to let you know they are not working, whenever the engine light is on the other systems can not operate if the engine is not working correctly, so its programed to shut down the trac and vsc when the engine light is on. the catalyst system means the catalic converter is no longer cleaning the exhasut to specs, this is caused by a weak bad converter or bad o2 sensors giving false readings you will need to have the sensors checked to see if they are the problem or the converter is the problem good luck.
For some reason on Toyota and some Lexus vehicles certain check engine light CEL issues also result in the ECU lighting up the vsc trac and vsc off lights. The ECU actually switches these anti skid and anti lock brake systems off and the lights are to remind you that they are disabled.
1) Check that the fuel cap is on securely
2) Check the oxygen sensors on the exhaust, check that connections are clean and there are no missing wires.
3) Have someone check the on-board diagnostic codes if the CEL is still on
You have to know what code is stored to fix the problem. Toyota's will generally display a Check Engine light, VSC and TRAC light all at the same time, even if it's a simple problem with an oxygen sensor (for example). You can disconnect the negative battery cable for a few minutes, even though you should a scan tool should be used, to clear out the code.
I have a 1999 ES 300 with the same problem. I took it to an independent repair center, (Big O Tires). They ran the codes and it told them it was one of three oxygen sensors in the car. There are two sensors for the engine, (one on either side of the V6 engine), and one for the catalytic converter. The bad part is this sensor is located AFTER the cat. converter, which means it could be the converter, (about $1500.00), or the sensor, (about $250.00). After checking all sensors, it was determined it was PROBABLY the sensor after the converter. I had the sensor replaced and so far the lights have not come back on. Seeing that your car is a 2003 model, I really don't think it could be the converter. If you have been dealing with a reputable repair center, go there. Otherwise go to the dealer and see what they say. If they recommend the converter, push for the sensor. That way you are only out $250.00! Good Luck!!!
Catalyst System Efficiency Below Threshold (Bank 1)
The catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream O2 sensor reading should be fairly steady. Typically the P0420 code triggers the Check Engine Light if the readings of the two sensors are similar. This is indicative of (among other things) a converter that is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.
A code P0420 may mean that one or more of the following has happened:
* Leaded fuel was used where unleaded was called for * An oxygen sensor is not reading (functioning) properly * The engine coolant temperature sensor is not working properly * Damaged or leaking exhaust manifold / catalytic converter / exhaust pipe * Retarded spark timing * The oxygen sensors in front and behind the converter are reporting too similar of readings
To Do list
* Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required. * Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady). * Inspect the downstream heated oxygen sensor (HO2), replace if necessary * Replace the catalytic converter