Earlier this week I decoded the check engine light error code to be P0430. I checked my K&N air filter (only 3 months old - 6000K miles) and discovered it was filthy. I replaced the filter with a stock filter from the stealer. I disconnected the battery terminal for an hour and started the car.
The check engine light was off and I noticed an increase in power. Two hundred miles later, the check engine light came back on.
Any ideas what could be causing the light to come back on?
I haven't noticed a loss of power or hear any thing out of the ordinary. Will I damage any components if I keep driving the car? I average about 100 miles a day. If it's an O2 sensor, what's the average repair bill?
See attached for detailed trouble code anaylsis.
Thanks In Advance!
I have the same problem at 127K miles. I have an after market exhaust with the same Y and 3 cat system with the sensors in identical locations. Nice improvement in the exhaust system . Recently, I replaced both cats off the manifold thinking they were the culprits of the threshold issue - unfortunately, the light came back on :chairshot: . How can I test the oxygen sensors? Any idea what my next steps should be? I will need to pass smog in the next year, so I would like to resolve this. Thanks.
Catalyst System Efficiency Below Threshold (bank 2
in 90 - 00 Lexus LS400
Posted
I have the same problem at 127K miles. I have an after market exhaust with the same Y and 3 cat system with the sensors in identical locations. Nice improvement in the exhaust system
. Recently, I replaced both cats off the manifold thinking they were the culprits of the threshold issue 
- unfortunately, the light came back on 
:chairshot: . How can I test the oxygen sensors? Any idea what my next steps should be? I will need to pass smog in the next year, so I would like to resolve this. Thanks.