The diagnosis of my car pulled a P0420 code (emissions below threshold 1); mechanic reset the codes, and I changed the spark plugs and wires. Car has failed OBD readiness once and I am taking it back tomorrow; car has driven over 200 miles since. Is that enough miles to reset the computer? Help!!!
200 miles is more than enough. p0420 is a cat code meaning the cat in the exhaust is not doing its job. you need to make sure there are no exhaust leaks before the downstream (last one) o2 sensor. if you can get all but 1 monitor to set without the check eng light coming on, you will pass pa emmissions.
SOURCE: 2 codes 1) P0420 catalytic converter
possible causes for code po420 airleaks at the exhaust manifold or in the exhaust pipes,base engine problems high engine oil or coolant usage,catalytic converter is damaged contaminated or has failed,continuos engine misfire conditions or weak or low coil out put,front HO2s or rear HO2s is contaminated with fuel or moisture,rear HO2s is loose in the mounting hole,front HO2s older aged than the rear HO2s or HO2s 1 - 2 is lazy.
SOURCE: Toyota camry 2001emission not ready (Readiness == Fail )
The system has to complete a certain number of drive cycles to complete the system readiness function, this is a mixture of stop and go, highway and idling, I admit it should have cleared by now, but try to do a mixture of driving, just highway won't do it, it should complete soon, if it doesn't then there is a problem that will have to be diagnosed.
SOURCE: EMISSIONS INSPECTION FAILED
you can try this unplug the batt. from ground. let it set for 30min.put it back but still you need to replace the main pproblems if this dont work
SOURCE: OBD 1 and 2 will not communicate with PCM.
a blown fuse will also cause the obd to not communicate
SOURCE: Failed Emissions test. OBD
Rich:
The trick to setting all the monitors is:
Make sure you have more than 1/4 tank of fuel but no more than 3/4.
Clear codes then Do Not cycle key off. Start vehicle and drive,make sure you do at least 2 minutes of steady spead between 40-50 mph and at least 2 minutes at 50-65 mph, usually about a 20 to 25 mile drive will set them..
If you turn the ignition off before the monitors complete then EVAP will have to see a 6 hour cold soak before it will attempt to run again.
The
code PO420 you have is Catalyst System efficiency is below threshold bank one.
Usually replacing the O2 sensor that's the front most in the exhaust system
will cure your problem,
Your Check Engine light
is on and you find a P0420 code for a catalytic converter fault. Does that really
mean your converter has reached the end of the road and needs to be replaced? A
new converter can cost $600 to $1000 or more if a new car dealer or repair shop does the
job, or maybe half that amount if you do it yourself. It's an expensive fix
that may or may not be necessary. The problem, in most cases, is an emissions
issue, not a performance issue that affects the way the engine runs.
A P0420 diagnostic
trouble code is a "generic" fault code that is set when the Onboard Diagnostic II
(OBD II) system sees a drop in converter efficiency. The
OBD II system monitors catalyst efficiency by comparing the switching activity
of the upstream and downstream oxygen sensors in the exhaust. The upstream O2
sensor in theexhaust manifold reflects the
condition of the exhaust gases as they exit the engine. The downstream O2
sensor in or behind the catalytic converter reflects the condition of the
exhaust after it passes through he converter.
The catalytic converter
is like an after-burner. It oxidizes (burns) any residual fuel vapors (unburned
hydrocarbons or HC) in the exhaust. It also burns any carbon monoxide (CO) in
the exhaust. The exhaust must meet federal emission standards, and if a problem
exists that causes emissions to exceed the federal limits by 150%, the OBD II
system is supposed to catch the fault, set a code and turn on the Check Engine
light.
Thanks
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