CEL P0420

[FLUXEMAG]

My car is trying to tell me something...

Anyways, I got code P0420 after I changed my oil this morning. Lately I have been taking off the heat deflector over the exhaust manifold so I can reach the oil filter easier from the top. I read that this code is related to the O2 sensor and catalytic converter efficiency. What did I do to break this sensor while changing my oil and will this be covered under the 60k mile powertrain warranty or the emmissions warranty? My car has 45k miles and the V6.

[FLUXEMAG]

Ok, I read the warranty and found the O2 sensor is not covered after 2years or 24000 miles.

Any thoughts about whether this is worth replacing? Does the O2 sensor even act to control anything about the engine, or is this just an emmissions notification?

[[SMAN]]

From what i've read, it says this about code P0420

"Catalyst System Effeciency Below Threshold (Bank 1)

Problem Area: Gas Leakage in Exhaust System, A/F sensor (Bank 1 Sensor 1), Heated Oxygen Sensor (Bank 1 Sensor 2), Three-Way catalytic converter (Inside Exhaust Manifold)

I have like a 6 page thing on how to test and repair the parts, let me see if i can't put it into a pdf or jpg or something.

*UPDATE: PM me you email address and I can send it to you.

[FLUXEMAG]

Well that's hard to resolve, because bank1 sensor1 and bank1 sensor2 are both located on the side of the engine closest to the windshield. I was working right next to bank2 sensor1 when I removed the oil filter. I'm going to take a stab at this and say the catalytic converter itsself is fine. hmmmm, I don't believe in coincidence, I'm reading the TSB EG037-04.

also, you have pm

[[SMAN]]

i sent you an email with the stuff i had.

[NeFaRiOuS_SLE]

It wants to have a pipe and some weed! J/K just felt like being a smartass.

(P = Pipe... 0420 kinda = 4:20)

[Fletch]

It's rarely ever the cat. OE O2 sensor would probably be at least $75 if I remember correctly. Sucks that they are so salty.

[PXLpainter]

You're going to want to replace that crap with the JPP headers soon anyway!

[[SMAN]]

Any luck figuring it out with the stuff i sent you?

[FLUXEMAG]

Yeah, it helped a lot. I think the TSB I found about identifying the banks must be wrong. I can't even see where the bank1 sensors are located, I may just replace the sensor next to where I was working and F the codes. Looks like these are 4 wire o2 sensors, so I may try the cheap universal replacement first. $35 instead of $153 for the Bosch one.

[FLUXEMAG]

Ok, update...I reset the ECU to clear the fail code in hopes that it was a false failure related to my oil change. The code and CEL have not returned so far and the engine is running smoothly still.

[SoCalSolara]

maybe I shouldn't post here......
mine is gen 1 ,2000 I4 and i have same CEL P0240.
Repair shop told me that cat convertor is bad by reading the code P0240. $ 450 (labor+parts)

After reading this thread, I doubt that maybe it's just the O2 sensor instead of cat convertor? I really not sure which one is bad, and how many O2 sensors are there for 2000's ?

thanks

[SoCalSolara]

maybe I shouldn't post here......
mine is gen 1 ,2000 I4 and i have same CEL P0240.
Repair shop told me that cat convertor is bad by reading the code P0240. $ 450 (labor+parts)

After reading this thread, I doubt that maybe it's just the O2 sensor instead of cat convertor? I really not sure which one is bad, and how many O2 sensors are there for 2000's ?

thanks

anyone??? please help
thanks

[FLUXEMAG]

my code was 420, yours was 240...different failures.

[SoCalSolara]

my code was 420, yours was 240...different failures.

yea, you are right. My code is P0420,too. I just had a typo for that...