Cats are the question

[jsbihn]

hey all,
i have the crappy cat thing going on.
basically the truck sounds like someone shaking a krylon can when it is running.
So I am wondering where the actual cats are on the truck

I am not stupid when it comes to vehicles, but I have found out from other vehicles that sometimes there are multiple cats or what might look like a cat is really a small muffler or a resonator.

So i would like to know where are all the cats are at on the truck, and if possible pictures would be great!
Thanks

[guruerror]

http://parts.nalleygmc.com/showAssembly.aspx?ukey_assembly=392701&ukey_make=1027&ukey_model=14605&modelYear=2005&ukey_category=0&ukey_driveLine=0&ukey_TrimLevel=0&ukey_modelRange=0&searchString=converter

#5 and 12 in the diagram.

[jsbihn]

How did I know guruerror would be the man :-)

Thanks!!

[jsbihn]

BTW, do you happen to know the diameter of the pipe leading into and exiting out of the cats?

And have you heard of anyone who has eliminated there cats, and if so did it effect anything and is there anything in addition to the cats being eliminated that has to be done (ie. like for the o2 sensors or any check engine lights)

[IRA51]

THE MAGNA FLOWS ARE GREAT AND FIT RIGHT http://www.rockauto.com/catalog/x,carcode,1431821,parttype,5808
THESE ARE FOR AN 05

Year

Description

Product Type

Standard/HM Part#

OEM Grade Part#



2005

8 6.0L; D/S

DIRECT FIT CATALYTIC CONVERTER

24084

51372



2005

8 6.0L; D/S

UNIVERSAL CATALYTIC CONVERTER

99006HM

51006



2005

8 6.0L; P/S

DIRECT FIT CATALYTIC CONVERTER

24083

51200



2005

8 6.0L; P/S

UNIVERSAL CATALYTIC CONVERTER

99006HM

51006

[jsbihn]

Thanks for the info but I am looking to get rid of the cats all together.

thats why I was wondering about the pipe diameter of the exhaust

[devilsfan]

Are you sure that's the problem? I had the same issue a few years ago and it turned out to be broken baffles in the muffler.

[Hellz]

Just disconnect them from the headers and use a crowbar and smash the ceramic inside the cats. No sense of ****ing around with more than you need to, even more so if your not going to replace the cats.


Hope you do t live in a area they do smog inspection...huge fine screwing with smog equipment

[jsbihn]

devilsfan,
I am pretty sure. I mean the sound comes from just under the drivers seat, it goes away usually when they get really hot, and every one i know that knows cars stated it was the cats.

if it isnt then hey no harm no foul since i will just have gutted something I probably would have gutted later on

Hellz,
do you think it can be done that easy?
I mean looking at the pictures of the cats makes me think that the bends on the pipes leading to them would be too much to get anything in there.
i have though of disconnecting and then using a power washer.....

given any ideas (from anyone) on what will happen once the cat is gone with the second O2 sensor?

[IRA51]

YOU WILL SET A MIL WITH OUT THE CAT . YOU CAN ELIMINATE THE CATS AND USE SIMS ,OR EFI LIVE AND DELITE CAT EFISHANCY MONITOR .THIS IS ILLEGAL AND I DON'T RECOMEND IT .

[jsbihn]

Ira51
ok, assume that I know parts of what you are saying
MIL? - i assume this is some check engine type light
SIMS - a reprogrammer
I know efi live from my vette
DELITE CAT EFISHANCY MONITOR - huh?

are you speaking about all these from experience or just from what you would think would be?
I am not doubting your knowledge, just asking because i have heard others on the forum talk about having no cats or vettes talking about having no cats and they would get away with tricking the OBD / O2 sensor setup by putting washers in to space the sensor back, or whatever

So I am asking if you know personally or just figuring thats what would be

also, yes i know it is "illegal" if somehow I was caught by a official who would actually know the cats werent there and then inspected them.
(given just about all my cars and race cars were cat less)

[Humdingah]

MIL = Malfunction Indicator Light ('Check Engine' light)

SIMS = You can purchase a SIM, which is a connector that will 'simulate' the cat still being there.

Catalytic Converter SIM (http://lmgtfy.com/?q=catalytic+converter+simulator)

'Delete Cat Efficiency Monitor' would be a setting in EFILive that would allow you to ignore any signals that arrived due to the cats not being there anymore.

[guruerror]

If someone actually moves forward with this and deletes their cats on their H2, please post back results. CELs, performance, MPG, sound, etc...

Thanks.

[IRA51]

I CAN TELL YOU FROM EXPERIANCE ,THAT UNLESS YOU HAVE A BUILT ENGINE WITH BIG HP theis isn't much to be gained by eliminateing the cats if they are not cloged . the Magnaflow cats flow pleanty good on a stock engine if your factory cats are cloged and need replaced . :raar:

[Stellar]

Thanks for the info but I am looking to get rid of the cats all together.

thats why I was wondering about the pipe diameter of the exhaust

If you want to remove your post secondary cats utilize spark plug antifoulers to fool the ECU, weld in some straight pipe and call it a day. I believe the diameter is 2.25" for the stock exhaust. I don't run cats or a muffler, the weight savings are a lil bonus, and the sound is awesome. :beerchug:

[jsbihn]

stellar,
please explain more
so there is 2 cats in this truck?
what is a spark plug anti fouler'

any picture?


IRA,
you have to turn off the caps lock man, unless you are demonstrating you are mad and yelling.
anyways, i am dumping the cats because my truck drives around town sounding like a krylon can be shaken up
plus i think thinking that maybe the white smoke i am getting for the rear after long drives at high speed and quick stops or slow down is coming from the cats.
either way they are FUBAR and so they need fixing, so i will get rid of them all together to eliminate another issue later down the road

[IRA51]

The fouler trick to restrict flow to the down stream O2 sensors works some times ,some times it don't . If you drill the foulers so the O2 fits ,you may destroy the fouler and then need to weld 2 foulers together to make it work . FYI the feds take a dim view of tampering the emission system on a vehicle if you get caught . The chances of getting caught are mighty slim . Non the less , in the long run you are better off replaceing the cats if they are bad. I have no horse in this race , and a'm just trying to steer you in the right direction . :twak:

[IRA51]

The fouler trick to restrict flow to the down stream O2 sensors works some times ,some times it don't . If you drill the foulers so the O2 fits ,you may destroy the fouler and then need to weld 2 foulers together to make it work . FYI the feds take a dim view of tampering the emission system on a vehicle if you get caught . The chances of getting caught are mighty slim . Non the less , in the long run you are better off replaceing the cats if they are bad. I have no horse in this race , and a'm just trying to steer you in the right direction . :twak: