P0420 code

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P0420 code

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P0420 code - 9/15/2008 5:39:45 PM

pteam

Posts: 125
Joined: 1/29/2008
Status: offline

Hey guys this is on our 2004 escalade limo which is the same engine / powertrain as the h2 pretty much. But the car is not overheating and running at normal operating temp but we were getting warm A/C lately and we just drained the system and recharged it a few weeks ago. We have a check engine code showing code p0420 the code means:

The catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream O2 sensor reading should be fairly steady. Typically the P0420 code triggers the Check Engine Light if the readings of the two sensors are similar. This is indicative of (among other things) a converter that is not working as efficiently as it should be (according to specs).

A code P0420 may mean that one or more of the following has happened:

An oxygen sensor is not reading (functioning) properly
The engine coolant temperature sensor is not working properly
Damaged or leaking exhaust manifold / catalytic converter / exhaust pipe
Retarded spark timing
The oxygen sensors in front and behind the converter are reporting too similar of readings

The engine is running normal operating temps but the fenders of the car get extremly hot hot hot!!! I just noticed this today and I dont think thats normal for the escalade as our hummer h2 fenders aren''''''''''''''''t hot at all. Anybody else have experience with this? Would this affect our Air conditioning? The air flow coming out of the exhaust feels fine and just as much as our h2s. Do you think it could be the o2 sensor or a clogged cat? Any suggestions would be helpful!

< Message edited by pteam -- 9/15/2008 7:16:17 PM >

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