Should I be worried?????

[skymoney]

Hey buds... my 99 runner with a little shy of 107K mi. had the check engine light come on... and when i hooked it up to the OBD, the code read PO420. I was wondering if I should be worried about this or is it just an O2 sensor and i should not really worry about it. I had the guy clear the light out, so we'll see if the light comes back on. My guess is that it does come on again but only time will tell. Thanks for responding guys!

 

[p nut]

Why would you not worry about a CEL popping up? It's not an urgent issue, but it's something that you need to get fixed. You might also notice a lower MPG.

 

[Ohio4R]

Yes the CEL will come back on in a couple of days and yes your gas mileage will decrease.

 

[skymoney]

well i put seafoam in my car and its been actually gettin better gas mileage. could that fix the problem of somethin goin on in the cat?

 

[Mr. Dabadina]

Curious, did you put the seafoam in the tank and then the CEL popped up? From what I've heard the seafoam does help but can cause sensor problems if its never been used before. B/C of this, I'm waiting to put some seafoam in the tank until I wanna replace my O2 sensor. IMO you do want to get that replaced when you can, but you can let it slide for a LITTLE bit. And yes you will see a drop in MPG.

 

[skymoney]

check engine light was on... and THEN i put the sea foam in. it seems to have made a difference in stuff but i wont know really until i fill up again and calculate my mileage.

 

[4rnr4me]

just out of curiosity, did you spray under your hood recently?

ive heard cases of water getting on the spark plugs and causing that code...

 

[skymoney]

nope... never spayed under the car but i have been thru a car wash... but i dont think that kind of thing would result from a commercial car wash.