Cylinder missfire fix or cat converter replacement?
 

06 HCH has codes: P0420- cat converter, P0304-cyl 4 missfire, P0301 cyl 1 missfire, and P0300 multiple cyl missfire, can i fix/replace cylinders and wait till 2 years for smog inspection to replace cat converter with no problems?? Car still works but struggles when electric assist is charging also leaks oil. Any advice is appriciated thanks !

Re: Cylinder missfire fix or cat converter replacement?
 

Replace all 8 plugs with NGK or Denso OE Style plugs (Laser iridium).

Re: Cylinder missfire fix or cat converter replacement?
 

Ok ill try that thanks !

Re: Cylinder missfire fix or cat converter replacement?
 

Plugs are expensive. Don't cheap out.

Re: Cylinder missfire fix or cat converter replacement?
 

I just checked all 4 plugs, they look good maybe the wires are bad? Is there a way to check?

Re: Cylinder missfire fix or cat converter replacement?
 

You're not paying attention. Please refer to my first post - as I said, there are 8 plugs. They can look perfect and still not function. Unless you know they've been replaced in the last 60K miles WITH THE OE STYLE PLUGS, replace them.

I've encountered P030X misfire codes on 3X HCH2, and in all three cases, they needed new plugs.

Re: Cylinder missfire fix or cat converter replacement?
 

**** honda, ok ill replace them thanks for the help

Re: Cylinder missfire fix or cat converter replacement?
 

https://www.rockauto.com/en/catalog/...park+plug,7212

NGK 4458

There's also a Denso P/N but I can't find it on RockAuto, and I can't get to denso's site.

If you buy them locally, they're likely to run you $14 EACH

Re: Cylinder missfire fix or cat converter replacement?
 

Thanks brotha I appreciate the advice!