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Troubleshooting fault codes on 1999 ES300

(1999 Lexus ES300)
in Houston, TX on May 10, 2011
My check engine light and TracOff lights are on. My codes are P1349, P0300, P0301, P0303, and P0305. My car has 122K miles; and I have just replaced all three oxygen sensors. The car drove beautifully for 2-3 miles after I replaced the sensors; then the lights came back on; and the car idles roughly, misses, and lacks power. I have seen answers here which say that the cause(s) could be failed ignition coil(s); failed oil control valve, or failed mass air flow sensor. I would like to know how to test these components, and in what order, to determine the cause of the actual problem. Thanks.
Displaying 2 answers & 2 comments
Popular Answer
on May 10, 2011
the codes have nothing to do with the o2 sensors.
they are missfire codes for the ignition system.
with 122k, i would start with replacing plugs and coils. this is basic maintenance required at 100k.
1349 is a code for the variable valve timing circuit. it needs to be checked by a shop with a scan tool to manipulate the solenoid. it could be sludge in the oil system that is causing this which could be an expensive repair. it may be a bad solenoid which is much less but whatever it is, it needs to be checked.
the trac light is a separate issue. a shop with a scan tool can retrieve the code to narrow down the failure for you.

on May 10, 2011
Just like Roy said. There are multiple misfires at Bank 1. Since there is a VVT code also and there are no misfire codes at Bank 2, I'd start to diagnose the VVT problem. The common cause is sludge and carbon deposit, which can clogs the orifices of the VVT control.

on May 10, 2011
Thanks, Roy and Zee! I really appreciate your fast responses. I'd add that I have always replaced oil and filter at 3K miles; hoping I would not have the sludge or gelling problem. I replaced the plugs and wires --but not ignition coils --- at slightly less than 100 K mile point. I replaced the oxygen sensors since it was supposed to have been done at 100 K maintenance. I had my valve cover gaskets replaced recently due to a leak; and there was no evidence of sludge. I have an OBDII scan tool; plus a VOM. Is there any way I can test the VVT solenoid myself to see if it works properly? Again, many thanks for taking the time to respond.
on May 10, 2011
If your scan tool can display real time data, you can match the Bank 1 and Bank 2 VVT cycle.
I'd suggest to get a good manual with trouble shooting charts and follow the steps.
You can find great repair manuals with step-by-step instructions, diagrams, DTC troubleshooting, parts locations and other important information here:
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