I am lucky enough in the state i live in not to have emissions but they may start anytime and i want a XE230/236 on a 112lsa. I was thinking if i put on the stock cat again and still can't pass if it would be possible just to add a muffler in the I-pipe and then have the muffler cut open and have a cat put in the inside and welded back up. Then have the muffler welded in with the cut/weld on the top side. I was thinking of this since you can't move or add extra cats correct? Would putting an extra cat on really help? Any input would be great. I am thinking of going with a xe230/236 on a 114LSA just for the emissions factor but if i could do something like this then i will just go with a 112lsa.

 

The problem with adding an extra cat too far from the engine is that it won't get hot enough to work. You could try it, but no guarantee it would get hot enough to do anything.

 

if ya wana get all crazy-
hook up your air pump to be on all the time and have it blow air in after the cat
emissions is parts per million so this should help.
you still would need a cat though
i'm going with true duals and dual cats

 

I'm doing cats on my duals as well. I might also see about "augmenting" the air flow, since I'll be one of the first f-bodies that I know of to go in for IL emissions testing with the new OBDII laws (basically, if you don't throw codes, you pass).

If you're looking to pull stuff off your car and not throw codes, reset your PCM and reconnect whatever you took off (i.e. AIR pump, EGR solenoid) and just kind of duct-tape it in the engine bay. As long as the thing itself is connected I think you'll be ok. Somebody please correct me on this if I'm wrong.

--Trax

 

I thought about a multi inline cat setup as well, but PITA factor. Run the car hot, and work with the timing, and I think it could pass, but I never tried.

 

Dig around on www.carprogrammer.com for other tips and tricks on smog.

 

Yep, if you'r OBD2 you'r home free if you'r not throwing a code and can pass a visual.

 

A catalytic converter will never light off if it's all the way in the back of the vehicle (by the muffler).

The catalysts used in the cats do both oxidation and reduction in different stages... you do not want to put one cat after another.

If you rig the AIR pump to run full time you need to disable closed loop, otherwise the PCM will see it as a major lean condition and DUMP the fuel in.

If you are going in for the new OBDII tests, where they simply scan the system, you do NOT want to reset the PCM immediately before testing. Not all of the onboard tests will have time be performed and they will ask you to retest at a later date.

Getting a 230/236 XE grind to pass emissions will take alchohol and plenty of tuning tricks IMO.

 

I don't understand this part could you explain it a tad more please. I was just thinking of moving the cat up closer to the stock original single cat so if you could explain that more to why it won't work. Just wondering how come you can't add more cats or move them or you will fail the visual isn't it just important that you pass the sniffer? Also for all the guys running true duals won't you not pass the visual because your cats are moved?

 

A cat helps with two very important emissions... hydrocarbons (ie, unburned fuel and CO, carbon monoxide) and NOx emissions (NO, NO2, think acid rain (nitric acid) when mixed with water vapor, very toxic)

A cat reduces these two components in different ways, through two different types of catalyst. A cat does not have a single catalyst, it's actually two, in stages, in one housing. The exhaust needs to pass through a reduction to eliminate NOx emissions before passing through the oxidation phase to "burn" the unburned fuel (the oxidation stage uses the freed oxygen from the reduction stage). By putting two cats in series the exhaust gas would pass through one stage of reduction, one stage of oxidation, and then through one more reduction stage and one more oxidation stage. Reduction needs to take place before Oxidation. If you wanted to run twice the surface are of honeycomb you will need to cut the cats open, move all reduction catalyst to one cat and all oxidation catalyst to the next one, I'm not sure how to do this without destroying the "brick".

Chemistry is fun

 

Well i believe some mustangs have 4 cats so how does that work they would have to have one cat after the other one. Not trying to argue just trying to think of a solution.

 

There is a PCM program that you can use that will help with passing emissions. You need to know what you are doing though.

 

What about OBDI cars?

I didn't know Illinois was getting emmissions...this sucks!

 

Good point. I don't know enough about that setup to comment. Are they all 2-stage cats? If they are, then I'm wrong I just wouldn't think you'd want to place a reduction catalyst after an oxidizer catalyst. I'm certainly no expert, if you can prove me wrong I'd appreciate it!

 

well i just checked on the camaro forums fox bodies had 4 cats so 2 on each side.

http://www.corral.net/forums/showthr...46#post1582846