Nissan Frontier Forum banner
1 - 20 of 22 Posts

·
Registered
Joined
·
45 Posts
Discussion Starter · #1 ·
So has anyone hollowed out their Pre Catalytic Converters, I need new ones but Im broke, so I was thinking about taking em off and cleaning em out.
 

·
Registered
Joined
·
8,529 Posts
Pre-CATs? I thought it was the real ones first and then secondary heater ones second.

If you gut a cat without tuning, you will probably pop some codes and get crappy gas mileage and etc....

If you gut post cats then you should be alright but you probably won't see too much of a difference in performance.
 

·
Registered
Joined
·
45 Posts
Discussion Starter · #3 ·
It has four. Im only guessing that its the pre cats, If I drive around, then park, kill it and get out, you can hear em crackling and popping like they are to hot. The truck has no performance as of right now. Its a dog. 4x4parts.com sells some headers that gets rid of the pre cats, the headers cost the same as replacing the pre cats. so if I some how come up with the money to get it fixxed right I wold just get the headers. I have the cat codes right now. I did O2 sensors and still got codes.
 

·
Registered
Joined
·
214 Posts
hmmm...

It has four. Im only guessing that its the pre cats, If I drive around, then park, kill it and get out, you can hear em crackling and popping like they are to hot. The truck has no performance as of right now. Its a dog. 4x4parts.com sells some headers that gets rid of the pre cats, the headers cost the same as replacing the pre cats. so if I some how come up with the money to get it fixxed right I wold just get the headers. I have the cat codes right now. I did O2 sensors and still got codes.


been a lot of threads on this. what are the codes? most likely if you are throwing a code, it's gonna be on the primaries. the ones being monitored by the sensors. the post cats or secondary cats are not monitored by sensors , therfore the CPU has no idea if they are good or bad.

logically thinking, the primaries are doing all of the cleaning first. the secondaries aren't cleaning much unless the primaries go bad, at which point you will throw the code. p0420 and p0430 i think.

check ur KS

i was tricked out by the Knock Sensor. my KS went bad and the engine adjusted itself so much the o2 sensors were out of whack and it threw the code. after i relocated the KS with a new one, the code was gone for a little while. i ran too long with my CEL on trying to figure out the codes that i burnt the primary cats and had to replace them.

I DID cut the secondaries out and i AM running straight pipes.

there are 3 types of cat set ups according to engine. for v6 3.3l there are 2 set ups.
cats that bolt on to the manifold and cats that are one piece with the manifold. i am not sure of the 3rd setup as that refers to the 4 cyl. engine and i have 6.

MAKE SURE U KNOW WHAT U HAVE. i went to the dealership up the road to price them out. they asked for VIN. i said "ok".
they said " these are what you need and they are X number of dollars"
i said " no those dont look right."
they said " well thats what ur VIN says so thats what you have."
i said "go find me a tech to show me where those are cause thats not what i see."

45minutes later, out to the truck we go, pop the hood and he says "hmmphf ur right, those arent the ones. u have the one piece."

NO ****

thank god mom and dad raised an idiot......sorry about the rant.


good luck
and yes you can remove the secondaries with out affecting the performance of the primaries.

i know, i did it and i am about to get a sticker in massachusetts. i will let u all know whether or not i truly pass. but so far no CEL
knock on wood....

p.s. my new manifold and cats (or manicats? or catifolds?) ping and pop a lot more than i ever remember when cooling down. not sure why? better grade of steel or materials?
 

·
Premium Member
Joined
·
6,081 Posts

·
Registered
Joined
·
214 Posts
:confused::confused::confused:
:laugh:
well they at least raised someone who didn't proof read their posts
well either i was raised the idiot or the tech from the dealership was, either way one of us was right about which cat was required for my truck....wonder who?

and i do proof read.....

didnt catch my sarcasm? its all good....besides i helping....i put someone to sleep and gave you a good laugh, so like George Costanza, thank you and good night....
 

·
Premium Member
Joined
·
959 Posts
They headers are made for "racing"/ you have to get after market cats for the truck to run right like the guy stated earlier. The cats that are built onto the manafolds are the most important. Dont hog em out..
 

·
Registered
Joined
·
443 Posts
So has anyone hollowed out their Pre Catalytic Converters, I need new ones but Im broke, so I was thinking about taking em off and cleaning em out.
you can do that, just get o2 sims, or spark foulers for the downstream o2's.

Not frontier specific, however on my maxima i did this.

My maxima came with two giant pre cats, and a main cat similar to the frontiers. I replaced my manifolds with headers. Since my car has 4 o2's, i just hooked up the upstream o2's, and added a o2sim to the rears.
 

·
Registered
Joined
·
336 Posts
you can do that, just get o2 sims, or spark foulers for the downstream o2's.

Not frontier specific, however on my maxima i did this.

My maxima came with two giant pre cats, and a main cat similar to the frontiers. I replaced my manifolds with headers. Since my car has 4 o2's, i just hooked up the upstream o2's, and added a o2sim to the rears.
O2 sims? (I'm guessing this is simulators?)

I was unaware of such a device. I wonder if I can get some for my '96 Maxima...
 

·
Registered
Joined
·
45 Posts
Discussion Starter · #12 ·
Yeah I had the knock sensor code and the cat code I think they are the ones you stated. I did the KS relocate I still had the code, I think I had the wires mixed up so I switched the wires and I need to go get the codes checked again. i will do it today. The front cat are pricy. We dont have inspections here in good ol boy Oklahoma. Thank GOD. So you can get away with alot. Tell you the truth this is the first truck I have had with cats. and like a [email protected]$$ I threw the cats I cut off in the trash. This was when I was young and didnt know better.
 

·
Registered
Joined
·
45 Posts
Discussion Starter · #13 ·
Well I found these for $75 each. Im think about getting them, I have a welder and all the other tools I need. I build custom bobbers. I just really dont work on my truck. I got alot of other things going on, house for sale, building me a new bike, and trying to find a new house.
 

Attachments

·
Registered
Joined
·
214 Posts
sleepy time....

O2 sims? (I'm guessing this is simulators?)

I was unaware of such a device. I wonder if I can get some for my '96 Maxima...

if anyone is NOT concerned with emissions then "Cry havoc and let lose the dogs of war" mod as much as possible.

42002 Spark Plug Non-Fouler here is the part. auto zone has them.

check the write up and some other links.

here's the deal with this.

your post O2 sensor is picking up too much oxygen from exhaust not being cleaned by the cat.

by removing the sensor away from the exhaust stream, you will reduce the amount of O2 that it detects.

two of these together with one hollowed out will "space" the O2 sensor away. unfortunately it may not last and if you are doing to remove a code, then i am pretty sure it will come back. mine did, BUT i did in december of 09 and got a sticker in massachusetts. code was off and all......then i ran it until march/april until i got my taxes back and the light came back on. but i had money to fix it so i did.


getting the O2 sensors on and off with the "spacers" can be tight.

passenger side may have shift linkage interference. might need to adjust design.

driver side, i had to drop front drive shaft for better access. not hard but PIA.

USE ANTI SEIZE on all threads. cant stress this enuff.


oh and if you have good primary cats and O2 sensors, then you can cut secondaries out and run staight pipe to the "Y" pipe WITHOUT doing the "O2 mod". I did it. can post pics if u want.
 

·
Registered
Joined
·
1,258 Posts
Subscribed...
Just lets us know what ends up working for ya. I was putting mid grade gas in my truck, it was keeping the CEL off, and getting great MPG but that is no longer working for me. It has premium gas in it right now, the light is still on, and is not getting very good gas mileage. I know the cats need to be replaced and the knock sensor is probably bad but I am moving to an oil town that doesn't care about emissions so I am not looking to spend any money on it.
 

·
Registered
Joined
·
336 Posts
I'm guessing I would be getting the Dual Output Universal O2 sim. Right? (for truck OR Maxima)
 

·
Registered
Joined
·
443 Posts
I'm guessing I would be getting the Dual Output Universal O2 sim. Right? (for truck OR Maxima)
yeah if you're removing both precats..

However for your maxima, you only need a single output. IIRC 98-99 cali spec maxi's came with 4 o2's. Not 3 like the fed specs.
 

·
Registered
Joined
·
45 Posts
Discussion Starter · #19 ·
Well the codes I had were the KS and the pre cats, I did the KS relocate and had the codes cleared and they havent come back yet. I havent really felt any gain in performance. I guess I will see if the codes come back. I havent done anything to the cats yet. I have been looking around here cause I swear I seen a thread about putting pacesetter headers for the 3.0 on a 3.3 motor with alittle modifying. Those headers are alot cheaper than 4x4parts.com.
 

·
Registered
Joined
·
214 Posts
yes

you are right. there is a write up about the headers. need a little bang there and a bend here, but heard they fit.

i would have done it had i lived in a state that wasn't too concerned about emissions.
do the research, would hate to see ya dump money into it and start throwing codes or having emission issues at state inspection station.
 
1 - 20 of 22 Posts
Top