which cats do I have to leave on?

Advertise with us
shop deals on amazon
Shop deals on ebay
Ford SportTrac Forum

Help Support Ford SportTrac Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
D

Dallas Starr

Well-Known Member
Joined
Nov 3, 2003
Messages
3,240
Reaction score
0
Location
Edmonton, AB
Seeings how I cant go to Louisville im treating myself to a new exhaust (finally getting mine installed).



Now which cats can I remove (I have no smog laws where I live). I am planning on getting the xcal2 but I dont have it right now. So without the xcal2, which cats can be removed with out sending off Check engine lights?



Any help would be greatly appreciated.



Dallas
 
The laws pertraining to cats are Federal. So you do have the law, it is just that your locality does not enforce them. My family business is in custom exhaust, trust me, I am correct.



The crytical cats are the finial cats. The first are pre-cats and they help the main cats do their job. We have four O2 sensors. They will register any changes in the cats you make.



If you remove the rear cats you will have OBD II codes. I am told a flash type computer can turn of the specific codes and thus the CEL would not turn on for these codes only.
 
a3b1d405a394fa78c227050857729548.jpg




Leave us all installed, or else I'll wake you up tonight with a nice ear byte!!



:lol::lol::lol::lol::p
 
I live in alberta, canada and we dont have smog laws here, they are not federal here, they are provincial. And so without getting the xcal2 I can not remove any cats? otherwise i will get CEL.... is that what your telling me? I coudl swear you could remove some. I thought we could get rid of like 2 of the 4 or something.
 
huh.....maybe I've just been lucky, I have a custom exhaust on my 2002 ST. It was fabricated and installed in Mexico a week after I drove it off the Ford lot ( 4 years ago and lived in a border town, it was less expensive to do then in the States. They removed the two back cats when installing the system and making it a dual rear exit. As of this time no CEL related to such modification. I've also past the vehicle inspection every time, most resently last week. So it may just be me, but no problems here.
 
The pre-cats on the Trac are pretty good sized by comparison of earlier model years. For example, Chrysler had baseball sized precats. All the did was start to burn off the fuel. The main converters completed the job. In your case, the pre-cats are doing the entire job as well as letting the O2's stay within range.



It has to do with the exhaust system as well. To free flowing and the exhaust passes thru before being able to burn off the raw fuel. The O2's do nothing more than register oxygen, or lack there of. They send a signal to the ECM and it either leans out or enriches the fuel ratio depending on temperature and load and what not.
 
Coastie thanks for the insight. I was under a similar assumption as to why no CEL. I had a similar modification done on an 02 'Stang and about 1 week later I had the CEL light come on. Had to install a O2 bypass to the sensors to turn the CEL off. Your insight explains my "Luck" for not having a CEL on my ST and not needing an O2 bypass while only having the pre-cats on.
 
so....can we just have the 2 pre-cats on and still be ok. oh and with the 2 cats off is it loud, because i have dual straight pipes (cat back), and it's not hat loud for straight pipes, should i take the last 2 cats off?
 
You can remove the two y pipe cats (pre cats) and the back most cat ( AFTER the 02 sensor.)

Todd Z
 
Yup
 

Latest posts

Top