Code 0420, What damage can it do?

Edman · Post by **Edman** » Wed Oct 29, 2008 7:52 pm

I had a problem code 0420, I didn't fix it. Could this have led to a blown head gasket? What happens when P0420 is not fixed?

Edman

daewoomofo · Post by **daewoomofo** » Wed Oct 29, 2008 11:27 pm

what is code 0420?

Daniel · Post by **Daniel** » Thu Oct 30, 2008 8:44 am

A blown head gasket could be the origin of P0420 error code:

From engine controls section 1F:

DIAGNOSTIC TROUBLE CODE (DTC) P0420
CATALYST BANK 1 LOW EFFICIENCY

5. If the three–way catalytic converter needs to be
replaced, make sure that another condition is not
present which would cause the converter to become
damaged. These conditions may include the
following: misfire, high engine oil or coolant consumption,
and/or retarded spark timing or weak
spark. To avoid damaging the replacement converter,
correct any possible causes of converter damage
before replacing the catalytic converter.

jidasas · Post by **jidasas** » Fri Oct 31, 2008 2:22 am

I've had that code thrown up now for over 2 years...had the dealer check the first cat...it was good as far as they could tell and didn't want me to replace it...checked my spark and all was good but the code keeps coming up don't know why but it hasn't hurt my engine that I can tell. Still feels the same. I don't use any oil between changes and the coolant never loses any so I have no idea why mine comes on? I think I may cut the first cat out completely since it's a minimum of $200 and then make a piece that will hold the second o2 sensor out of the exhaust flow and see if the code goes away?

Jimmy

Big Jeff · Post by **Big Jeff** » Fri Oct 31, 2008 11:15 am

i had a problem with my cat so i took it off and bash the shit that was inside, i still have 1 section left in the cat, just needed to remove some of it. work fine

Edman · Post by **Edman** » Mon Nov 03, 2008 7:53 pm

I ask, because it was the only code I had before losing water!

my 2000 Lanos 1.6, now blows water vapors out of the exhaust. But no water in my oil? I drove it a mile, after adding water again. I checked the oil again, black! No moca milk shake or water drops.

I'm told I blew a head gasket. About 2 years ago I rebuilt the head with new valves etc..... I'm going to cross my fingers and replace the head gasket again..... Wish me luck!

Edman

benzino · Post by **benzino** » Tue Nov 04, 2008 3:19 am

Is it possible for the cat to be blocked and not throw a code?

jidasas · Post by **jidasas** » Tue Nov 04, 2008 12:39 pm

if it's the second cat yes...not sure about the first one...i would think it would throw a code.

jimmy

benzino · Post by **benzino** » Wed Nov 05, 2008 4:45 am

jidasas wrote:if it's the second cat yes...not sure about the first one...i would think it would throw a code.

jimmy

Aus delivered cars only have one cat

Big Jeff · Post by **Big Jeff** » Wed Nov 05, 2008 4:20 pm

mine too