[trunkout]

to make a REAL long story short......i have had my check engine light go on/off for about a month now....went in for an oil change.....seems the light is caused by a bad cat......I have 71k on my insight....
Honda: "we will cover it under your 8/80 warranty"
Me: "i don't have that"
Honda: "now you do"

i drive away.....the new cat feels like a new engine!!!!!

so I call the dealership.
Honda: "we put in an 05 cat.....about twice as much flow thru from an 01"

IS THIS TRUE???? it sure feels like it......

 

[trunkout]

yeah and so....

my check engine light is back on now......

:roll:

 

[Getshocked.ca]

Well, if your check engine light hasn't indicated your 02 sensors yet, may i suggest you have them checked from a 3rd party mechanic?? have them manulay test them (this is coming from a guy on Cat #3

 

[Subterfuge3927]

my 05 cat I put on after my 0420 code fixed my engine light and did seem to give a tad more bottom end power, mothing spectacular. Only thin I noticed is I could once again achieve LB hypermiling that had been robbed from me as the computer attempted to clean my emissions. :evil:

 

[Insightful Trekker]

From a deleted multipost thread masscommuter asked:

Is it worth replacing the catalytic converter in pre -'05 engines?
I wonder - at what cost?

The answer to your question would be no, don't replace the CATs.

There are several possible explanations as to a specific type of _concurrent_ CAT failure that Trunkout was also experiencing that _could_ explain his stated significant improvement. But without first hand inspection of the CAT we'll never know for sure. A P0420 _almost_ never indicates a restricted CAT (although it could). If so the complaint from behind the wheel would rarely be a MIL, loss of power _and_ still be driveable.

Subtrafuge's reply is the most commonly correct in this situation. All the possible interactions of learned PCM "values". An answer to Trunkout's experience is beyond simple qualification. You'd have to do an extensive "research" project to know.

Is there a difference in 00-05 CATs :?: Maybe, you'd have to check the part numbers. Better to compare 02-05 since there were some changes after 00-01 that _may_ require a different PN. (an extra hole for another O2 sensor is one that comes to mind)

Do the 05 CATs "flow" better as Trunkout has been led to believe :?: Again maybe. The PN's would be the only "armchair" answer.

If the 05 CATs do flow better and you replace it for an otherwise good 00-04 CAT, would you see a significant overall power / MPG improvement :?: IMO little or none. There isn't _one_ "simple" thing you can do for as dramatic an improvement. Such improvements require something more complex e.g. a turbocharger. Or that the car is so poorly designed to begin with there's no place else to go _but_ up :!: As you already know, not so with an Insight.

HTH!

[edit typo, sentence structure]

 

[masscommuter]

Thanks for nailing this one.
I'll hold off on needless replacement of cat converter.
javascript:emoticon(':wink:')
Wink

I had cross-posted to "Modifications" (wrongly) to get the expert opinion and here it is - (sorry for cross-posting).

 

[Aaron Cake]

so I call the dealership.
Honda: "we put in an 05 cat.....about twice as much flow thru from an 01"
IS THIS TRUE???? it sure feels like it......

That's the 2nd most ridiculous thing I have heard from a Honda dealer. There MAY be a flow increase, but there's no way it's twice as much and the dealer has no way of knowing anyway (unless you see a flow bench in the corner).

 

[trunkout]

yup

kinda felt the same way, aaron......

well i get it back tomo with TWO new cats......i'll let yall know......

 

[Insightful Trekker]

So your saying that the MIL that shortly returned _after_ the first CAT replacement again indicates bad CATs :?:

Hmmm, I'd require some further diagnosis on their part. Such a failure is extremely RARE. What is more likely is a mixture too rich "overloading" the CAT. The code is merely a reflection of an otherwise good CAT unable to perform the extra work (there is a limit of CAT performance).

The LAF is first on the list. (Primary O2 sensor)

Plese keep us informed.

HTH!

 

[trunkout]

yep

everythings fine now....

seems one of my rear bearings was failing the same time I had my cats replaced.....so the mileage/sounds/speed issues are all gone.

AFTER cats and bearings all is well....up 3mpg....road noise gone...

feels kinda new.....that bearing was noisy I guess....I thought it was a by product of lite weight!