Check-engine light...Code P0420
#27
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Re: Check-engine light...Code P0420
A Worn out engine will damage a cat! So does that mean he should replace his engine? Fact is, the ECU tested the cat and it failed. And if the car is running too rich or too lean there would have been other codes stored, In my experience as a Honda master tech, I know this car needs a new cat and I would check the coil and igniter as the probable cause of premature cat failure. Hey, maybe the cat failed because its a crap cat! Seen that too.
#29
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Re: Check-engine light...Code P0420
A Worn out engine will damage a cat! So does that mean he should replace his engine? Fact is, the ECU tested the cat and it failed. And if the car is running too rich or too lean there would have been other codes stored, In my experience as a Honda master tech, I know this car needs a new cat and I would check the coil and igniter as the probable cause of premature cat failure. Hey, maybe the cat failed because its a crap cat! Seen that too.
Scenario: 97 Civic with auto trans and cat on the exhaust manifold comes in with a huge crack in the manifold and has a code P0420 (Accord/Civic with broken manifolds are extremely common). There's no O2 sensor code, only a P0420. What are you going to do?
I never said the cat was not the problem, it could very well be the problem, but you can't rule out all other possibilities.
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Re: Check-engine light...Code P0420
Damn! Its like im trying to teach a monkey how to read. A leak in front of the cat will not create the same waveform on the rear O2 sensor! Its just not possible. The ECU expects a flatter waveform at the secondary O2. If the front O2 LT fuel trim is more than 100, like an exhaust leak, It wont kick a P0420. Period! I dont care what you have read!
#31
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Re: Check-engine light...Code P0420
Damn! Its like im trying to teach a monkey how to read. A leak in front of the cat will not create the same waveform on the rear O2 sensor! Its just not possible. The ECU expects a flatter waveform at the secondary O2. If the front O2 LT fuel trim is more than 100, like an exhaust leak, It wont kick a P0420. Period! I dont care what you have read!
There's a huge Honda and a Huge Acura logo painted on our building.
We also do exhaust work.
I'll leave it at that.
PS - Your e-***** is much larger than mine.
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Re: Check-engine light...Code P0420
I finally had an excuse to drive my 'Lude on the freeway last night to test the CEL after reseting it. I drove 55 miles without the CEL coming on. I was sure that it would too, so maybe the CEL engine code P0420 was a faulty happening?
#34
Re: Check-engine light...Code P0420
Slomofo,
I think you're the only one in this thread providing objective advice. Thank you.
Do you know why a leak before the cat causes catalyst inefficiency? I'm looking at a leak between the o2 and cat possibly causing a P0420.
I think you're the only one in this thread providing objective advice. Thank you.
Do you know why a leak before the cat causes catalyst inefficiency? I'm looking at a leak between the o2 and cat possibly causing a P0420.
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Re: Check-engine light...Code P0420
From my experience, this is a clogged EGR system. This is rampant in the H22A. There was a TSB about it.
A bad/clogged cat is something you can usually feel (from lack of power) hear (poor exhaust note) and smell (rotten eggs).
The H22A at this mileage is known for a clogged EGR system. It requires you to pull the plugs by the intake manifold, clean out the system, and press in new plugs.
A bad/clogged cat is something you can usually feel (from lack of power) hear (poor exhaust note) and smell (rotten eggs).
The H22A at this mileage is known for a clogged EGR system. It requires you to pull the plugs by the intake manifold, clean out the system, and press in new plugs.
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