I saw a couple old threads but didn't wanna revive anything old so I figured i'd post a new one and I didn't understand the other's. Check engine light came on and my code reader gave me P0420 so I'm wondering basically what I should check. Some background....

The light came on when I was driving home around midnight and the engine was still a little cold, and I had the heat up to defog the window. My car has a cat on it but I recently had a new muffler put on to pass inspection. The light came on before I had it changed but I'm wondering if the swap coulda fixed it or if the issue would lie further up near the manifold. I saw some stuff about O2 sensors, but I'm not really sure what to check or how, so if anyone could give me an elementary rundown, that would be awesome.

I'm hoping this is something I can do myself instead of taking into a shop.

 

From what I understand, besides a faulty cat, your O2 sensor could be going or you could have a leak... Did you pass your inspection?

 

yeah to pass, I just had to get the new muffler. Took it to two places and in regards to exhaust, the only issue was the muffler according to both canadian tire and midas. How would I check the O2 sensor? or can i? the code reader has "levels" of severity and it said that the code isn't critical, but I should really get it fixed asap.

 

do you have a highflow cat? i got this code when i put my new cat on. fixed it by taking the rear 02 sensor just a bit out of the exhaust stream

 

The light went off on it's own for awhile but just came back. Is this what i would need to move the sensor?

http://www.roadracemotorsports.com/s...b6144acc85e0df

 

that one didnt work for me for some odd reason so i ended up using this one

Weapon-R UNIVERSAL C.E.L. ELIMINATOR
Item Number: 963-111-101

havent seen a p0420 code since

 

Thanks.

it does look longer than the RRM one....did you order it directly from weapon-r?

 

i dont remember where i ordered it from. I just googled it and saw who gave me the best price

 

haha i do that for EVERYTHING i buy.
-Flip

 

make sure its not because the actual sensor is faulty. If it is change the sensor, that sensor is directly related to fuel economy....since the you got the cel how is the car on gas?

 

I track my fuel economy with an iphone app...last time i filled up i got 7.7L/100km or 30.7 MPG

 

Wow congrats if it's the darn truth lol the beat I can usually get is 23 mpg and that's granny shifting and staying below 40 mph mivec is like my z06 , nonexsistant.