Removing the cat

[Ca_Silvia]

I did do some searching and never found anything on actually removing the peice. I live in a place where they don't do emissions testing so this is legal. I brought my car to my local exhaust guy to get the cat cut out and he said you can not remove this style because of the o2 sensor being located after the cat. He said if we did cut it out the motor could burn white hot (i assume he is refering to the spark plugs).

While his explaination did seem to make sense i have had a CA18DET in my old Silvia and it was cat-less with seemingly no problems. So i ask the CA guru's is it safe to completly remove the cat from our motors? Can you remove the o2 sensor or do you have to weld a bung to keep the o2 sensor?

[240 Trainee]

If you have a CA, you should only have one o2 sensor, the one up on the o2 housing off the turbo. Why don't you just get a high flow cat and save the trees.

[Ca_Silvia]

Garunteed i have 2 o2 sensors, can anyone else chime in here? Plus me and the trees never seem to get along.

[ilovecoupes]

If you have a CA, you should only have one o2 sensor, the one up on the o2 housing off the turbo.

[Ca_Silvia]

If you guys are doubting me i can take a picture to prove it to you. I know im not crazy here

[240 Trainee]

Well, go take a pic then, lol, stock CA did not have 2 02 sensors, maybe the person before had a wide band or was running an EGT gauge in the wrong place or something, I dunno.

[Ca_Silvia]

Looks stock to me

http://www.putfile.com/ca_silvia

Its the main picture on that page i cant load pictures properly at work.

[Zero260]

considering the ca motor came WAY before OBD II systems there is no reason to have an O2 sensor in the cat. did you swap a CA motor into an s14? is so, that o2 sensor isn't plugged in to the CA ECU, and you could remove it.

and the guy saying that whatever would run white-hot is full of crap. rear o2 sensors are designed to tell you if you're cat is working or not, they have nothing to do with engine parameters. at worst, you're check engine light will come on, but it won't mess up jack.

[Masterdebater]

f*** o2 sensors.and knock sensors.

[Zero260]

f*** o2 sensors.and knock sensors.

you'd have to have one SMALL pen15

[davidricardo86]

Looks stock to me

http://www.putfile.com/ca_silvia

Its the main picture on that page i cant load pictures properly at work.

IIRC I've read something about this also. I think the some Silvia models with a catalyst came with a second one. I know you're not crazy cuz i heard or read it somewhere. Maybe the FSM. I'll try and see if i can find this information for you.

As for the removing the cat, your car should run fine without it. Obviously the catalytic converter is for reducing emissions and doesn't have any affect on the engine, but it does affect our earth!

[The_Chosen_One]

you'd have to have one SMALL pen15

is that really necessary? For all we know you could be 10 times smaller than him.

[Ca_Silvia]

So i went to the track last night and talk to a couple of tuners form the local import shop they said it would be fine to cut the wire. I might have the exhaust light come on the dash and thats about it. So i think i will still get it cut out and just snip the wire.

Daivd did you find anything in the FSM? I would look but my home computer crashed with my FSM on it.

[Hogg]

Id be curious to know why the stock Silvia would have a second o2 sensor near the cat, havent heard of that problem even from people running straight pipes on their 180s, and modified 240s. I assume it would have something to do with the CA platform and/or the turbo that comes with it.Just to stabilize the amount of air consumption a little better or more balanced with a second reading or something?

People with real S13s dont have this problem Aaron

-Spence

[Ca_Silvia]

People with real S13s dont have this problem Aaron

-Spence

So i guess i should just sell the motor and get an SR so all my problem go away? Or maybe if i start now i can beat you in getting the VK swap done...

[ca18datsun510]

cat overheat sensor.

they use them in jdm land.

if you look on a lot of jdm clusters, honda, nissan, whatever, there is a cat light.

[Hogg]

Really starting to lose faith in my 4.5litre swap, seems that with adapter plates and custom driveshafts, big transmissions, new clutches, differentials and stuff it will turn out to be far more than I had anticipated

So now Im thinkin a full RB20DET/CA18DET swap for $1500 sounds much more fun

Maybe back to my cheap and effective KA24DE-T idea...

Dont ya love how retarted teenagers change their minds every 20 minutes.

Modified by Hogg at 1:47 PM 5/13/2007
Modified by Hogg at 3:28 PM 5/13/2007

[disrupt]

keep your cat. it is not cause a significate power restriction.

It is just like the people who release refrigerant from their ac systems instead of getting it drained at a shop.

We are live here on earth and if everyone purged their ac and run without a cat it would make things even worse.

Think about this. I bet everyone here lives in a place with smog. Even with some attempt to prevent to reduce it, it is not happening. At least make effort.

Just my 2 cents.

[float_6969]

Seriously, don't ditch the CAT. You can buy a 3", High flow cat from FRSport for less than $150 that will bolt right up and it comes with new gaskets, nut, botls, and washers.

I did and saw very little difference in performance. It actually cut down on my boost spikes in 1st and 2nd gear. I didn't notice any loss in top end power.

[Ca_Silvia]

Seriously, don't ditch the CAT. You can buy a 3", High flow cat from FRSport for less than $150 that will bolt right up and it comes with new gaskets, nut, botls, and washers.

I did and saw very little difference in performance. It actually cut down on my boost spikes in 1st and 2nd gear. I didn't notice any loss in top end power.

I appreciate everything what you guys are saying, really. But its the sound that i am after.

[Woods Crasher]

Yea that 2nd o2 sensor is there despite it being an old car. It's there because the cat can get real hot and it will trip a light on the dash. That light is almost always on on my ca18 cluster.

[float_6969]

I appreciate everything what you guys are saying, really. But its the sound that i am after.

Hey what do you care about the air that my Daughter is going to have to breath later on down the road, right? I mean, you're cars gonna sound good, that's totally worth it,right!