Hello,

I have a 2016 Honda fit with 103,583 miles, and had a check engine light come on, so I used my OBDII scanner and it came back with the dreaded PO420 code. I took it to the mechanic and they suggested replacing the catalytic converter and the O2 sensors. So I did because that seemed to be the best course of action, however it’s been 4months and now the check engine light is on again for the same code,I do not notice any loss on mpg or oil burning at all. I’m out 2,000$,and I’m trying to see if this could be something I could possible fix. Is there some reset or something? When I look at my OBD scanner tests it tells me the catalytic converter is passing and so are the O2 sensors. is there any advice or help I could get? Any and all advice would be greatly appreciate.

 

hmmmm....random advice is fuel injectors dumping too much fuel.....can you see the "long term fuel trim" if it high....MAYBE bad injector.....i have a 2015 just waiting and waiting for the dreaded injector failure

 

What about disconnecting the battery, wait, and reconnecting it? Long shot.

 

yes ..lol.....my moneys on bad fuel injector(s) ....leaky...but worth a try!!!!!!!!!!!!!!

 

Thank you so much for the replies! Is this long term fuel trim good or bad, when googling it I kind of got mixed results.

 

The ideal fuel trim should be zero but on older cars where everything is worn that may be difficult to achieve. This is not an unreasonable number.

Most OBD scanners can reset warning lights and turn them off. Of course if a problem persists the light will eventually come on again but then you know whether you still have a problem or not.

 

is there bank 2,3,4,? i was thinking if one was wayyyy different,that might be a clue...but it might be an overall reading of all of them ,,,which does not look too alarming...its trying to take OUT fuel though...which says something (what exactly it says i must admit i am not sure!!)

 

Because it has fuel injection each cylinder receives it's own flow of fuel which is individually monitored and individually controlled by the fuel injection system. So I guess to answer your question, yes, there should be 4 separate readings.

 

It's not the catalytic converter, it is the fuel injectors. Your mechanic got it wrong. You need to do a fuel injector balance test. I had to get my fuel injectors replaced at around your mileage back December of last year. Same code came up on the scanner. You are looking at almost $2000 to get the fuel injectors replaced. Even if you do it yourself, it'll cost over $1000, that's how expensive they cost.