Hey guys I had this check engine light on my car for the past 2 weeks with the p0420 code I reset it a couple time but when i am driving on the highway it always comes back then i decided to fill my car up with 93 octane and all of a sudden 2 days ago the light just went out and hasnt come back again does this mean it is all fixed , i went to autozone to get a reading and nothing came up , was wondering if you guys had this experienced this before

 

Have you been running Regular or Premium fuel up until the 93 fill up?

 

interesting you had this problem. i just bought a new(used) suv for my wife -- 06 nissan pathfinder. the douche, err.. car salesman, did fill it up before we left. i'm sure that moron put 87 in the vehicle. so later that day, as we were driving on the highway, an SES(service engine soon/aka nissan's: CEL) came on w/ a P0430 code, which i've read are somewhat similar to P0420's. i know i'm talking about a different vehicle, but I just recently filled it up with 93, which it'll be getting from now on. i wonder if i reset the code on my SUV if it'll go away too?

i've read that 87 gas can cause these types of error codes sometimes. hope that's true in my case anyway. cheap/easy fix!

 

Yes i was filling up with 87 at first then I switch to 89 after reading a few post here , then i decided to go with 93 octane the check engine hasnt come back yet 150miles driving with the 93 octane

 

Keep using what teh manufacturer recommends

 

I actually had the reverse problem. I was using 87 for the last couple of months and then put 93 in and the CEL came on. I just went though that tank and put 91 in it so we will see what happens

 

And you are assuming the fuel did this? Using the wrong fuel then going to the correct fuel wouldnt cause that. Next time the light is on, while its on have the codes read.

 

P0420 is a DTC for a plugged cat. It's a code the 02 sensor in the cat will send to the ECU when there is unusal air velocity or heat passing thru the cat.

 

got it looked at today. It was the Cat. Covered under warrenty 8yr/80k. It was just wierd that it happened with the new tank of gas.

 

i have the code p0420 andalso have been only using 93 octane. is it due to the 10% ethenal they put in the gas?

what you mean by cat is the catalytic converter? how do you get it unplugged and how much did it cost

thanks
carol

 

Cat = Catalytic Converter

It's not the 10% ethanol. It's expensive to get a new OEM cat, so I'd explore different options...

 

you dont `unplug` a cat- you replace the entire thing because its internals melted together or came apart into splinters
DO NOT replace based soley on codes that its bad

have a muffler shop inspect its temp and pressure-
they have to do this to every cat they replace to document the failure type for the govt.
its usually free for the test

if a cat is needed, see our sponsoring vendor Excelerate for several choices from basic for cheap to racer for a lot more $~
any shop can install it- straight bolt on design