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All sensors have been replaced with new cat converter. Still getting a 0430obd code.

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I had the same problem. I replaced the plugs and the plenum gasket as well and it fixed the problem. all is well now. It seems that there may have been a leak in the plenum gasket allowing to much air in during lower RPM. This diagnosis is encouraged, but not confirmed by the fact that at higher RPM, the car runs better, meaning there is less unmeasured air bleeding in vs measured air coming through the MAS.

Posted on Jan 09, 2013

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If both upstream and downstream oxygen sensors have been replaced, I would suspect the converter is not appropriate for your vehicle. It is common that when an aftermarket universal type converter, or a low quality replacement is used, it does not perform well enough and sets off a converter efficiency code. Even if it is labeled as "heavy duty" Some vehicles are more sensitive to this than others. Ask the shop that installed the converter exactly what they used, and if necessary, replace it with a high quality converter designed specifically for your year, make, model and engine.

Posted on Mar 12, 2011

  • John Jan 09, 2013

    I had the same problem, I replaced the plugs and the plenum gasket and all is well


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2007 tahoe o2 sensor, installed new o2 sensor but engine light stays on. code says bad

which sensor was replaced
there are 2 sensors involved
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the code will read the same for both

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My 2000 2.0 JETTA is failing inspection and the code pulling up is P0422 but I was told the Cat is in good shape, any suggestions?

code p 0422 refers to main cat converter, bank 1 ---efficiency below thresh hold ===causes cat converter,--- wiring -- heated oxygen sensor (HO2S) 2
heated oxygen sensors are the ones in the exhaust manifolds before the cat converters
they are wired and the wires are delicate and can be easily damaged
O2 sensors (O2s) are found after the cat converters and can determine the quality of the cat performance
At this point I would be looking at the HO2S replacement as that is what the code indicates --IF-- the cat is in proper working condition

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Location of 02 oxygen sensor on 00 Linc ls v8 need replacing

O2 sensors are after the cat converter and if you have 2 cat converters they will be after each converter
have you had the fault codes read to get that code or are you guessing that that is the problem
mostly with O2 sensors a wash and scrub in vinegar will get them working again but the HO2S sensors ( heated sensors ) in front of the cat converters give the most problems from the current in the wires or other circuitry faults
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1 Answer

New exhaust no cst converters chanch sensors twice problem stay p0420

you will need a cat converter to make the system work properly
code p 0420 refers to cat converter system bank 1-efficiency below threshold===causes ---cat converter, ---wiring---HO2S 2 sensor
have you been replacing the correct sensor as they are different in operation

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2004 nissan xterra run great for 12 miles then misfiring,cnt get over 45 miles an hour. codes p 0733,p0420,p0430,p0328 comes up. new wires,new cap,rotor spark plugs 6 months old timming belt 6 months...

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code p0420 refers to catalytic converter system -bank 1---efficiency below threshold===causes--cat converter--wiring--HO2s 2
code po430 refers to cat converter system bank 2--efficiency below threshold===causes--cat converter--wiring ---HO2s 2
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basically replace the cat converters as they are blocking the exhaust system and preventing your over 45mph problem
replace the TR sensor/ switch as you have not mentioned a transmission problem
Rectify the problem with the KS as it controls the air/fuel mixture setting which contributes to the car getting hot.

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1 Answer

My 2000 Toyo. Tacoma Prerunner TRD V6, truck Failed smog due to the part #3 Functional Computer Tests due to an erased MIL. But had passed the Visual Inspection, and Emissions. So i bought a Code reader...

there are 2 sensors in the system
one is a heated oxygen sensor (HO2S) in the exhaust manifold / pipe before the cat converter that reports the exhaust gas composition to the ECM so that fuel/ air ratios can be adjusted
if that one is faulty it is most likely the reason for running lean or rich
the second sensor is the oxygen sensor (O2) which is after the cat converter and reads the results of the cat converter cleaning the exhaust
you may have to replace both the sensors to get a clearance or replace the cat converter as well as the HO2S unit

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1 Answer

O2 sensors keep failing and a evap leak code i put new gas cap did not cgehan

Are you sure it's 02 sensors? Just because code says 02 sensors doesn't necessarily mean they're bad. Bad 02 sensor code can also indicate bad cat. converter. If 02 sensors read exact same reading before and after converter they will trigger OBC to "sensor fault" - they should be reading 2 different readings. (Pre CAT/POST cat) I'd suggest replacing cat converter before replacing sensors.

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1 Answer

1999 miata has check engine light on. i turned it off and it stayed out for about a month. took to autozone had two codes exuast and cat. converter. whats wrong with this car?

exhaust doesnt sound like a code, there should be more to code than cat or exhaust, the cat code is probably like cta efficencey below thrushold. this means the converter is not working, the cause maybe bad cat or bad oxygen sensors, testing may be needed to see if o2 sensors are working good. the exhaust code i dont know, never heard of exhaust code, they may be caused by the same problem, start with the cat code, have o2 sensors (oyxgen sensor) checked or if over 100,000 miles replace them. if converter is bad it a very good thing to also replace the o2 sensors with the new cat.

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3 Answers

Hello, where is bank 1 sensor 2 located on my 1996 inline 6 f150 I am pulling a 0141 code as well as a 0174

Will be the o2 sensor all the way to the back on the exhaust system, after the Catalytic Converter.

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