dustysaw

Hey guys, just wanted your input as to what kind of catalytic converter i should get for my exhaust. Failed E-test - most likely the aftermarket cat. I've got megan headers and a magnaflow exhaust - 2.25 inch piping. I would prefer going the safe route and getting some kind of factory cat, whether it be for honda or toyota. I would also prefer for the diameter to be the same, but if I need to do some custom work, so be it. NEED the problem fixed.

thanks for your input - much appreciated as I am in quite the clusterf**k

I live in Ontario btw

here is the link for the cat I have.

http://www.magnaflow.com/02catalytic...niversal=53005

ezone

Cat code P0420, or a failed cat on a sniffer test?

Get a factory cat if it has to keep the CEL off, or a cat that is California CARB certified (49 state cert is garbage). Factory is best.

Is junkyard an option?

dustysaw

I don't have any codes. I dont know too much about it but the e-test that we have to do every two years has three categories, and one of them has a nitrous oxide count. Failed it miserably. Problem is I can't get factory - at least not what's supposed to be factory for my car cuz i have the aftermarket headers, where before the cat was built in...

ezone

I have to wonder how the car can be without any cat code, but the cat failed a sniffer test.

I hear of many cars that have set cat codes but can still pass the sniffer test.
The PCM is far more picky than most emissions test standards.
But the PCM can't monitor NOx emissions, it can only measure Oxygen storage capacity in the cat.
Factory cat is best for NOx reduction too.

Do you have a rear O2 simulator on it or something?

Maybe something is really wrong....
High combustion temps cause excessive NOx. Could be caused by things like
High compression
Running hot
Lack of EGR flow
Probably more.
If those are perfect, then it probably needs the cat.
I don't live in an emissions testing area, so I don't have to deal with it.


Install a factory cat for an EX (or whichever Can. model) under the car would be my next OE choice.

If you seriously think you need more flow than a stock cat can handle (I doubt it), how about some other factory Honda cat from something with a larger engine, like a 2.0-2.4, maybe from a CRV or an Accord?
(Hint: A correct original factory cat flows more than enough for a stock displacement naturally aspirated engine, unless maybe you have it turning 9000rpm.)

lazlong

American EX= Canadian SI. Get the EX cat and extend the O2 sensor wires as it sits under the car.

Usually high NoX is due to running lean- bad injector(s) or not enough fuel pressure are the usual suspects.

SlimRisk

Hondas cats are also really free flowing so i would go oem. I would check exactly what ezone said we just learned this stuff in my autos 4 class.
The EGRs purpose is to reduce combustion temps to reduce NOx.

lazlong

Agree. Try cleaning the EGR. If that doesn't work try cleaning the EGR passages.

ezone

Yup, lean would make for high combustion temps too.

I bet loose sparkplugs could do it too, for that matter.

If this persons header has the O2 sensor located on only one of the 4 pipes, then it can't sense all of the cylinders properly.
IF the one cylinder were to be running rich, the computer response would be to try to drive them ALL lean.
Front O2 sensor needs to be relocated to the pipe inbetween the collector and the cat.

dustysaw

Okay thanks guys. I am gonna have my mechanic check it out soon. Hook up the comp to it to see what kinda codes he gets. For the record, I dont have an egr valve, its a dx.

ezone

You real sure of that?
Part #1 is your EGR valve and gasket.

dustysaw

Positive. I'd take a picture if my car was here! haha. Where it's supposed to be, its just flat.

SlimRisk

Only the Exs came with egr. I have an 01 lx and it doesn't have egr

ezone

Interesting. I haven't seen one with a block off plate here.
Must be a Canuckian emissions thing, eh?

Back to finding a factory cat to hang under the car.

dustysaw

Likely yeah :P Hopefully thats all that it amounts to.

04 Honda Civic

iTrader: (2)

I have a facotory EX cat but I am in NY. Might be a bit pricey to ship.

dustysaw

Yeah probably better just to get one on this side of the border. Thanks though. Btw whats the diameter of the entry and exit of the EX cat? My exhaust piping is 2.25 inch

lazlong

Get his cat (the cat only), it shouldn't be very much to ship ($20-40). Then you can get the other parts locally. The large pieces, like the resonator or down-pipe, are what really cost to ship