How to tell if your cat is clogged?
 

Hi!

Was wondering how do i tell if my cat is clogged? My mechanic was saying not much was coming out of my exhausts. He said he can take off my cat and check it sometime next week, but if i know how, maybe i can save the trip and check it myself. What do you look for in a clogged cat? How do i know if i need to replace it? I do notice the car is feeling kinda slow these days and the exhaust sounds kinda softer.

Also which cat should i buy if it does need replacing?

I heard of ETD racing metal bore cats or should i go with the flyin miata cats? Which is better? Why? The one i have in the car right now is the flyin miata one.

Thanks!

had that happen on a honda before (well, more like fall apart inside and clog the outlet).....the car loses A LOT of power, pretty drastic, if its clogged you'd definitely feel it.
that and very weird exhaust note.....

yes i do feel teh car slower
but how do i kno forsure when i take it out, what do i look for in a clogged cat?

i heard that if the car is runing too rich or lean can also affect the life of the cat and how often you redline the car.


and once i find out if i realy need a cat, i need to know which one is the best out there for my miata.

thanks!

running rich/lean has negative effects on a cat yes....redlining? uh never heard of that.

im pretty sure if you take it off and look into it, you should be able to tell if something is wrong... a typical/normal cat will look like web/honeycomb inside.
http://z.about.com/d/autorepair/1/5/...tic-inside.jpg

Ha you guys use cats.

and then a clogged cat will look like?:S
im prety sure my cat is clogged, hopefuly i can take it out tomroow and take a look at it and take some pics and post it asap

any else i should look for in a clogged cat? and if i do have to replace it, what cat should i be buying? a flyin miata cat again, or metal bore cat from etd racing or anything else? which cat is teh best for my miata?

thank you!

when my cat broke and keep clogging itself, it would start to fall on its face, going up hill or if I gave it more then 10% throttle. Mine broke, as a sold mass and was blocking the flow.

I saw an article in GRM about cats for an N/a miata and they showed that all the major cats, flying miata, moss, JR had the same effect on the car. There was only a 1-2 horsepower different from stock and a 1-2 torque difference.

Granted this was on an N/A car but they showed that all the cats are about the same even between the universal cat and flying miata cat.

joe the picture link is dead

it coughs up hairballs?

Erm, try to see sunlight through it. If you can't, it's clogged!

Alternatively, you can get a bag of sandblasting media and pour it into the throttle body with the engine running. If it doesn't come out of the tailpipe, the cat must be clogged. It's also good for polishing the airways inside the engine, or so I've heard.

The major difference between the Flyin Miata and the M-Tuned/ETD Cat is the material the Core is made from. The Cat used by M-Tuned is Metal and designed for use in Turbo applications. I've also seen only a 1hp difference on a 300hp SRT4 between a no cat and a ETD cat setup!

Yes! Only 1hp was lost when the cat was bolted on! The dyno chart looked almost the same. I was shocked!

You can purchase the M-Tuned Cat at http://www.m-tuned.com/miatacat.html

Please note with only have a 90-93 and 94-97 version available. No 99+ models!

I can't tell if you're joking or being serious.

Marc, what is the pipe size on those cats?

I saw someone say they did that in import tuner magazine, hillarious. Stupid people should be shot.

:bowrofl:

Well it's not a clogged cat,I just finished swapping out his cat and it looks good & clean,we also swapped in a test pipe and it made very little difference in performance.

Does anyone have any suggestions on what the fuck it might be?

hey guys

yeah we jus took out the cat and put in spikes extra test pipe lyin around

the car maybe feels a bit faster, but my car still feels slow...

before i was at 13psi, i boosted to 14 psi and the car feels slower after tuning, could it be a bad tune? Seems like the power doesnt wanna come out of my exhaust. I have flyin miata dual turbo exhausts on my car. Another thing we installed onto my miata before tuning was a dual feed fuel rail from tunertoys and a mac valve solenoid from the gm solenoid. We have no idea why im making less power! :S

We have them available in 2.5" and 2.25". I guess I should get the Website updated to list both versions.

wow how is that cat so hot? which cat is that?

I'm going to guess that it is clogged! :firedevil

A friend of mine on a track day removed clogged cat and jabbed the crap outta it with a long screwdriver, problem solved (of course if you don't have emissions tests).

Marc, any difference in spool with that cat swap?

sure was!


this is what happened when i simply dumped it out....

http://www.boostedmiata.com/blown_en...logged_cat.jpg


suffice to say, it got the broom handle treatment.

So those chunks came out before you went all Justin Volpe on it?

yep

Ont the SRT4 I personally watched there was zero difference in spool. The dyno chart looks the exact same. 1hp difference is so minor. I was freaking amazed!

Yes, modern Cats flow so well removing them is very hard to justify. To gut out a clocked cat or to save the cash of having to buy a new, I guess can be explained. But I personally, I think gutting a fully working cat to get a 1% improvement in power, as I have seen people do, is just unbelievably selfish.

Just my 0.02. *stepping of soap box*