[96BlkDak]

I bought 4 bottles of HEET to throw in (355ml ea.... all they had) After I picked them up I found 99% isopropanol at the drug store.... grabbed 2 bottles of that (500ml ea.)

The gas tank is about 80% full... can I mix the 2? and will what I have be anywhere near enough or am I going back for more?

way too much gasoline you want to run it down under 1/4 tank. get that alcohol % as high as possible.

get the engine good and warm then dump it in run it around about 1-2 miles then get it tested.




your truck is an OBD2 is your computer ratting you out or are they testing the tail pipe???

 

[l1tech]

2000 > 2001 :nana:



My stock exhaust had the upstream 02 in the Y pipe then the cat then the downstream 02

My duals are setup almost exactly the same way, headers with the down tubes nearly the same as stock, the X pipe is in the same location as the stock Y pipe with the upstream sensor in the X pipe. It reads both banks same as stock.

Only the 1 test this time, but it passed 2 years ago maybe 6 months after I put the exhaust on.

So you don't have "true dual" exhaust

 

[Bos-R/T]

So you don't have "true dual" exhaust

I assume you mean with the x pipe?

I just cant believe it being a year younger than mine it only having 1 cat.Looking at my MSRP sticker that came with my truck at the smog index,it ranges from 0.0-1.0 and mine showing .79.And from what everybody tells me is that I had 3 cats from the factory.

 

[AmberFireDaK]

way too much gasoline you want to run it down under 1/4 tank. get that alcohol % as high as possible.

get the engine good and warm then dump it in run it around about 1-2 miles then get it tested.


your truck is an OBD2 is your computer ratting you out or are they testing the tail pipe???

Like I said, I don't have 2 weeks to drive the truck everyday and drain the tank. I can get it a little lower but not much. Is it even possible to get enough alcohol in with the tank the full?

They actually do a sniff test... that's where I got the numbers in my first post

So you don't have "true dual" exhaust

If your one of those people that think it's not true dual because it has some form of balance tube, then sure. But it is a true dual exhaust

I assume you mean with the x pipe?

I just cant believe it being a year younger than mine it only having 1 cat.Looking at my MSRP sticker that came with my truck at the smog index,it ranges from 0.0-1.0 and mine showing .79.And from what everybody tells me is that I had 3 cats from the factory.

you do... you should have 2 pre-cats... one on each down tube... then another main cat behind the Y pipe

 

[Bos-R/T]

you do... you should have 2 pre-cats... one on each down tube... then another main cat behind the Y pipe

I didnt understand why I had the 3rd one because theres not an 02 sensor near where the third cat would be.I figured there would be atleast a downstream in it instead of there being 2 downstream on the precats.:huh:

 

[AmberFireDaK]

I didnt understand why I had the 3rd one because theres not an 02 sensor near where the third cat would be.I figured there would be atleast a downstream in it instead of there being 2 downstream on the precats.:huh:

I've given up trying to understand that on these trucks.... a lot of it seems completely random

 

[mthandt]

I've given up trying to understand that on these trucks.... a lot of it seems completely random

It is completely random, my 02 has 1 big cat and that's it, but I have seen other 02's have three or two. Oh yeah and my magnaflow cat does work right either. I'm pretty sure i would not pass the sniff test. Kinda pisses me off that the damn thing doesn't work.

 

[kota360]

I just depends on where you bought your truck. I bought my R/T in Canada and we have the same emission standards as California. I have 3 cats, 1 on each down pipe with an o2 sensor before and after each cat, then the both go into another cat and then into a 2 3/4" post cat single pipe. The ECM is also specific for that truck. If you bought an R/T any place else in the US, I'm not sure how many cats you would have but you get a different ECM to run the truck. I'm not sure what the exhaust configuration is on a 4.7 or a V-6.

 

[Bos-R/T]

I just depends on where you bought your truck. I bought my R/T in Canada and we have the same emission standards as California. I have 3 cats, 1 on each down pipe with an o2 sensor before and after each cat, then the both go into another cat and then into a 2 3/4" post cat single pipe. The ECM is also specific for that truck. If you bought an R/T any place else in the US, I'm not sure how many cats you would have but you get a different ECM to run the truck. I'm not sure what the exhaust configuration is on a 4.7 or a V-6.

On my window sticker from the dealer it says mine has 86% parts from Canada/U.S. Final assembly point was in Warren,Michigan And the country of origin for the engine is Mexico and the tranny is from U.S.

 

[kota360]

That doesn't mean a whole lot, it's the final delivery destination that governs emissions requirements.

 

[Bos-R/T]

That doesn't mean a whole lot, it's the final delivery destination that governs emissions requirements.

I was trying to point out how many places my truck came from.I thought it was funny

 

[AmberFireDaK]

Well I went for another test.... ran the tank down to just below 1/8th and dumped in 1500ml of 99% Isopropanol. still failed..

HC 71 - limit 50
CO% 0.51 - limit .28
NO 1088 - limit 0548

Not as bad as the first time, again only failed at speed, curb idle was all good

 

[Bos-R/T]

Well I went for another test.... ran the tank down to just below 1/8th and dumped in 1500ml of 99% Isopropanol. still failed..

HC 71 - limit 50
CO% 0.51 - limit .28
NO 1088 - limit 0548

Not as bad as the first time, again only failed at speed, curb idle was all good

Damn Yhats fucked up.STILL....

 

[Five9Dak]

Wait, if it has a Y pipe, how is it a dual exhaust?

 

[vortmax]

All cats don't do the same thing. Traditionally precats just oxidize NOx. The "pretreated" gas is then passed down to another cat that further processes the gasses. Its more complicated, but its more efficient and produces cleaner air. The single cat systems use a 3-way cat which takes care of everything all in one shot. So the factory system is really designed as a system. If you change it, you have to take that into account. You can't just mix and match parts (at least on a Cali truck).

There is also the issue of getting oxygen to the cats. To perform the oxidation reactions, there needs to be free oxygen in the cat. Some systems used an actual air pump, while others (like in our trucks) actually store extra O2 from the lean portion of the cycle. The cat can actually break down and lose the ability to either store sufficient oxygen or fully oxidize the gas while in the cat. In this case the cat can lose efficiency even though it is still flowing well. This may not be enough to trip an O2 efficiency code (especially since the system only checks efficiency a few times each drive cycle and requires 2 repeated faults to throw the code), but it could be enough to fail a sniffer.

Although from those numbers, I would think something else besides cats is going on.

 

[AmberFireDaK]

Wait, if it has a Y pipe, how is it a dual exhaust?

HAD a y pipe with the stock exhaust.... now has an X with my duals

 

[AmberFireDaK]

All cats don't do the same thing. Traditionally precats just oxidize NOx. The "pretreated" gas is then passed down to another cat that further processes the gasses. Its more complicated, but its more efficient and produces cleaner air. The single cat systems use a 3-way cat which takes care of everything all in one shot. So the factory system is really designed as a system. If you change it, you have to take that into account. You can't just mix and match parts (at least on a Cali truck).

There is also the issue of getting oxygen to the cats. To perform the oxidation reactions, there needs to be free oxygen in the cat. Some systems used an actual air pump, while others (like in our trucks) actually store extra O2 from the lean portion of the cycle. The cat can actually break down and lose the ability to either store sufficient oxygen or fully oxidize the gas while in the cat. In this case the cat can lose efficiency even though it is still flowing well. This may not be enough to trip an O2 efficiency code (especially since the system only checks efficiency a few times each drive cycle and requires 2 repeated faults to throw the code), but it could be enough to fail a sniffer.

Although from those numbers, I would think something else besides cats is going on.

care to share? lol

 

[AmberFireDaK]

I forgot to mention I also changed the PCV and drove the piss out of it on the way to the test so she should have been plenty hot. I seafoamed it earlier in the week too

 

[96BlkDak]

Take it to someone to tell you whats wrong.


:sorry:

 

[l1tech]

First thing that has me thinking is that the nox are high. Your truck doesn't have a EGR on it so one of 3 things has to be going on for this to happen 1) the truck is overheating while testing...I doubt it 2) the fuel mixture is lean and causing high cylinder temps which is causing high nox...you have an abundance of CO coming out the tailpipe so I don't think this is the issue 3) the cats are bad...a very real possibility. If you can find place that will check the gas before and after the cats, this is the only sure way to know exactly what the cats are cleaning up.

Forgot to mention that it is impossible for all 3 gasses to be high with properly functioning cats AS LONG AS THE VEHICLE IS IN PROPER FUEL CONTROL.