jaredvabeach

Today I got a P0420 code (no other codes were listed or pending)on my recently acquired 01 civic lx,to say the least im pissed I was not told about this prior to the sale.

I bought the car with the intent to replace the cam position sensor. The prior owner said that after driving for considerable amounts of time the car would begin to loose power and start to bog down until the car has fully cooled. No mentioning of a CEL was present.

I drove today 28.8 miles and yesterday about 10 miles. On the way home I received the CEL but have yet to see signs of a bad CYP sensor or any symptoms that represent a problem.


So my question is would a bad oxygen sensor,or a bad catalyst converter cause the car to give symptoms of a bad CYP sensor.

The upstream/primary O2 sensor has a blue insulated wrapping,so as you can imagine it is not factory,however the downstream O2 sensor appears to be factory but was not held on the factory wire restraints. I know a simple way to rule out if its factory or not is to check the part number on it.



None the less what is the likely hood of the Catalyst converter being bad compared to a bad oxygen sensor.




Again it has yet to display any problems,the moment I got the car I changed the oil,the air filter and installed some NGK Iridium spark plugs. It does not have any exhaust leaks and only has 128k miles on it and the engine seems very very healthy.

Maple50175

Hey man I had the same problem when I got my car. It was a bad 02 sensor I think. But im not sure becuase i took mine out and ran an o2 simulator from 02simuator.com I have had no problems but I did replace my primary o2 to some bosch one from autozone. Check that out.

The Blue wrapping is normal for our cars that came factory!

jaredvabeach

I do not want to use some quick aftermarket replacement strategy. If its broke ill replace it but I do not want to cover it up.


BTW: Your saying the blue wrap is factory? Is the black as well?

spoonfedcrx

Yes the blue shroud is from the factory.

What symptoms were you having or told about that was making you think it needed a cylinder position sensor?

So when it fully warms up it starts running like ****? and it's perfectly fine when its cold?

If you were having o2 sensor problems I would expect to see a code. As many headgaskets as I've done on those engines I wouldnt buy one of those without doing a leakdown test. Something maybe you should consider.

skipbarber

iTrader: (1)

blue shroud and plug is factory for 04-05 with wideband primary AFR sensors, not HO2S. Rule of thumb, replace your o2 sensors at 60k, it improves your fuel economy and overall engine efficiency. Id replace the downstream sensor first and go from there.

jaredvabeach

Well the downstream has the blue shroud,and the upstream has the black. The interveral for the heated oxygen sensors is 100k.


I was told it would run poorly and attempt to stall until it had completely cooled down.

skipbarber

iTrader: (1)

they say 100K is the interval to replace o2 sensors, but Ive never seen a car make it that far without throwing codes for faulty or sluggish o2 sensors. as far as the poor performance, the 01's are the ones that suffer from faulty CMP sensors more frequently, I know a lot of 7thgeners in my area just replace them when they do timing belts even if the car isnt showing any symptoms.

jaredvabeach

Well im getting the catalyst converter replaced tomorrow for 282.XX installed at Big Al's mufflers and brakes. I wanted a warranty and that was a price I just couldnt beat.


As far as the Cam sensor im going to wait untill I get significant signs of malfunction and replace it then. The belt was replaced at the Dealership at 85k miles so I dont exactly need to do it again.




So is my upstream oxygen sensor stock or aftermarket? It has the blue shroud.