Going to try out pacesetter converters. Any idea if switching to a smaller converter is going to make any real difference? Just showing the size difference even though one old one is from firewall area and the other is going on the front.

 

If the piping is not restrictive engine performance should not be affected. However, with less catalyst area it may not function as well or as long as the OE part. AFAIK they do not sell a CARB legal catalyst, which means they probably only use 'enough' material to keep the CEL off.

BTW if you are replacing the catalyst due to a P0420 code, verify first that the catalyst is dead. If the engine has not had a proper tuneup, plugs, cleaned EGR ports, verified valves are properly adjusted, then a p0420 code may be set.
IIRC Honda changed valve clearance adjustment from every 100Kmiles to 30Kmiles.

P0420 simply means the catalyst output has fallen below threshold efficiency, that's it.
An out of tune engine(worn plugs, valves out of adjustment, EGR ports clogged, air or fuel filter clogged, etc) will cause a P0420 code.

 

All schedule maintenance was done about 6 months ago. Converter is starting to almost glow red. Last time I checked the inlet temp was around 250 and outlet is around 550. Just trying to get by for not till I can buy the overpriced converter from the dealer.

 

If the converter is glowing red then there is probably an excess fuel problem.
Reverify engine tune, pull plugs inspect for fouling and do a compression check.
VCM j35s had issues with the VCM causing cylinder washdown from excessive fuel.

 

All plugs look great. I took converter off and I can't even see light through it lol. Only big thing I noticed as far as plugs was that one was hand tight. It was not even torqued and the plug boot was brown like it was getting blowby or whatever it is called. Engine is not tapping and there are no other codes other than p0420.

 

A loose plug would cause compression loss and fueling issue.
If the PCM was not reset(pulled fuse/disconnected battery) the CEL/Code will not immediately go away.

 

Also the valves do not tap when out of adjustment, they are too tight. Usually exhaust valves erode/wear at the seat and sink into the head. Clearance between the valve and rocker is reduced to the point the valve will not properly seal when at full operating temp, which will lead to misfires/P0420 codes being set. Speed Density system on Hondas, although robust, are not the most accurate when it comes to self diagnostics.

And unless it was stated on the 'scheduled maintenance', the valves may or may not have been adjusted. Unless you did it yourself.

 

As far as the dealer can tell everything is fine now. If my responses are short it's cause I'm at work lol. I wanted to be safe. Got ntk o2 sensors all around and my emissions were a little high. Me and a friend pulled the main cat and it was just about fully clogged. Waiting on new one to see how it runs. Does changing the oil consistently help reduce issues with valves?

 

Bigger is better... at least that's what she said.

 

In the rules of that's what she said you can't that's what she said yourself.