Were you not aware that he knows more than all the major tuners out there???

 

man this kinda stuff drives me absolutely

No offense to anyone but I never knew the air in Canada was different then ours lol! Its so stupid the laws for emissions! In Tennessee they have a 10,000lb exempt rule. If you weigh over 10,000 your exempt. Hmmmmm think of all them tractor trailors out there blowing tons of emissions into the atmosphere! Oh yeh and what about all the other states that have no emissions at all! Yet some states are going to pick on you like crazy. Someone seriously needs to walk up to our congressmen, state officials or any other bureaucrat and slap them square in the face! Seriously...I mean hey time to wake up, its all one planet folks with no air dividing lines.

 

I installed LG streets and put the NEW rear O2s into the front, and deleted the rears.

Mine are ceramic coated, so they stay hot inside and keep the O2s working and up to speed faster on cold starts. No codes EVAR.... 1.5 years.

 

That matters how? Incidentally, that's a pretty broad statement to make. Either way, neither you nor him are attempting to help answer or solve the issue; seem more interested to come in and point out where someone MAYBE wrong and that that you posses superior knowledge. Either help out or shut up.

 

Even more disgusting are the states, like mine, where only some counties have testing. Which I'm not in one. Back in my days in Texas though whenever I needed an inspection sticker it was always $25. cash for a $5.25 sticker. Everythings for sale.

 

That may be the one good reason for some type of coating, but I'm wondering if you get no errors due to tuning.
I think both mine and Xtreme's issue is that the tuning may cause us to fail the Ready test (at least me in TX). I don't have a problem with getting a tune, I just do not want the hassle of making changes to the car every year before an inspection.

 

Well, just goes to show Millenium Z06 that you don't read very well .... nickolbag was supporting you .... he was using something called "sarcasm" .... you might want to read up on it .....

And there is no "solution" .... I explained in a post above why LTs cause virtually every car to throw codes for catalyst inefficiency at some time or another.

Again, as I said above, have your rear sensors "tuned" out of your PCM ... or expect that you will see codes thrown on some occasions .....

I think you should go back and re-read this thread ..... and try actually COMPREHENDING what is being written.

 

I have changed sides!!! I now support you

All kidding aside. I got a little lost in this thread. But from what I understand I thought you will throw codes for the rear O2's unless you tune them out, even if you have them plugged in.

 

We good nickolbag

 

My bad, I didn't know he was referring to you as an ???
You'll understand if I just don't roll over and accept your answer.

 

lol this is starting to become funny, let me further try to help, as I think blackZ06 could use some more information too to clarify.

Think we have more then a few code problems dealing with here.

Group A: the front sensors: like me, and tons of others who had their rears turned off/tuned out. But still get slow response/insufficient switching on the fronts. Typical codes: P0153 and P1153.

Group B: those that still have all 4 sensors and are getting codes on the rear sensors.

 

Yeah, those are 2 seperate problems.
If you put in NEW sensors when you install headers that are coated, you should have no problems. I even had my high flow cats coated, just incase I have to reinstall rear O2s for emissions testing reasons. That way they will retain heat and work correctly. Actually I had the whole system coated all the way to the catback connection.

 

As the guy that started this thread and gained a lot from what it (thanks to ALL) by way of the information above, I would like to see the question narrowed to:

"Group B: those that still have all 4 sensors and are getting codes on the rear sensors"

since the original question was prompted by my consideration of having American Racing header Kit with "X" pipe and high flow cats with 4 sensors installed. At this point I'm considering keeping the exhaust system stock (except for my Ti's) so that I can go down the road with a smile instead of a code (even if I loose 15-20 hp).

 

It appears that with the combination of AR Headers, catted X-pipe, proper install/tuning it should be okay. Maybe coat the headers as an added measure. That is what I did and so far...although early....it is working!

 

Well I'll be honest, I searched and searched before I bought and installed my LG headers. I guess I didn't search for the proper thing though. I was more worried about fitment then anything. I "thought", keyword is thought....that in the great state of Tennessee that you didn't need emissions testing. I was wrong. Some counties you do, some you don't. I lucked out and got one that you do....go me! I dunno....if I don't pass, I might be putting all my hard work up for sale which really would not make me happy.

 

You'll pass as long as you have no current codes, mine pass' with the codes I get from time to time. I'm more concerned about the change that tuning will have on the ready status to the rears if they are tuned out. Currently we can have 2 not ready s and still pass; if the tuning takes out the rears and IF they report as not ready due to the tuning then we have a problem. That's what I'm trying to find out and what options we have. I just do not understand your issue, same setup and I have no issues at all with front codes and cannot figure out why you do unless it's the sensors.

 

The cause for codes like P0153 and P1153 is exactly the same as the cause for the problems with the cats ..... LTs move the O2 sensors further away from the exhaust ports than stock. Just as this affects the efficiency of the cats, it affects how the PCM sees the O2 sensors working.

With a P0153, for example, the PCM expects to see a switch from lean to rich (or vice versa) at a "calibrated" point in time. It may seem hard to believe, but LTs move the sensors far enough downstream to at least put them on the "borderline" of the timing the PCM has as "acceptable". That's why some people get codes constantly, and others get them intermittently, and some people get none at all.

Bottom line, the PCM is programmed to work with a "stock" exhaust layout ...... stock exhaust headers, stock cats, and the 4 O2 sensors in "known" locations. When you f**k with the system, you better expect it is gonna complain. The PCM is programmed to spot subtle changes in the performance of the cats and O2 sensors, and can even spot a bad fuel injector (P0200) using the O2 sensors. Either you "tune" the PCM for your non-stock exhaust (and deal with emission testing however you want) or accept the fact it is gonna throw codes sometimes.

It is not a system that GM designed to be monkeyed with. The EPA with OBD2 did all they could to prevent modifications to the engine and exhaust slipping by the monitoring system. GM is living to the letter of the law (OBD2).

 

Yep the sensor replacing is my next option Iam going to do. Just hate buying parts that might not solve an issue. Especially 02's they don't give these suckers away lol!

 

Yep follows suit with just about everything else I have read. Now I just got to learn more about the tuning aspect of this problem. I would like to know the proper way to "tune codes" so that they
1.) Don't trigger a check engine light anymore
2.) Have the tuning of the codes not interfere with the PCM's system so that the car will still be in "ready" state and thus be able to pass emissions.

I have learned a ton today....very helpful indeed. It took about 6 main threads and about 50 posts, but definitely well worth it. I think Millenium will agree, he seems to be right in there with me on this.

 

Did you put your headers on? if so what did you do with your O2 while they were out? I replaced my rears with Bosch units and remember reading in the instruction paper that they, O2's, will become contaminated and not work properly if left exposed to the atmosphere too long. Don't know how much truth there is in that warning but it's a thought.