Cat system on exhaust - 1st Gen to 1.5 Gen

[Scotto]

Here's a Question for you.

I don't have the cats in the truck. I'm thinking I could use the secondary cat system from the 1.5 Gen X as cats on my 2000X. Would they just slide in and would it work? I'm thinking about the e-test due in 6 months and maybe being a little more legal. I also have to replace that section of the exhaust soon anyways, so maybe this route would work. I have one code, which may or not be easy to remove, but I could always go for the conditional, but I would never get it if there are no cats whatsoever. I've looked long and hard about where I might be able to put an aftermarket cat on the pipes, but everything bends and twists. I just can't see a spot.

Oh how much easier the exhaust was on the Jeep. And the e-test, which it always passed with flying colours.

What say you?

Scott.

[Bow_Tied]

What is the CEL code?

You shouldn't have to have the snif test, just the OBDII scan check for ready state monitors. So anything that appeared to be a cat would work... unless you need a functioning cat to clear the CEL.

Flange mount the cat and then is it easily swapped after the fact.

[Scotto]

The code is a faulty evaporation valve. I guess the best thing to do would be fix that and then clear sailing thru the test.


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[Bow_Tied]

They will still likely do a visual inspection.

[buttsy]

Fixing the evap valve isn't too bad. Mine was a rotted wire in the harness. THAT'S a pain in the ass. Would've been super easy had I have waited to do the body lift first...

[Snafu]

Is a visual inspection normal now if nothing comes up from the scanner?

Without cats should it not come up with a code? If not then this OBD is just screwed up.

I agree that the first thing to do is address the codes then look at anything else the guys might balk at. Are you taking it to White's in Fergus?

[Jayman]

When we did the headers on my truck, we removed both sets of stock cats, and then had a shop install Magnaflow cats in pretty much the same locations as where the secondary stock ones were originally located.

So instead of 4 cats, I'm currently running only 2, and they are lower down the exhaust line then where the primaries were.

They suck for e-testing by the way, so don't get Magnaflow cats unless you have a work around for the codes you will get.

I haven't passed an e-test on the Xterra since I started modding it. I've pretty much just accepted that it will fail, that I will be paying for a conditional, and moving on from there.

[Nd4SpdSe]

A cat needs to be as close to the motor to do it's job.

I had no problems with my Magnaflow cat on my Mx-3, but I've heard that they don't use much for the needed materials (platinum) and last about a year for emissions testing.

But even then, now with the plug-in OBDII e-testing, with the magnaflows to pass the visial inspection, and throw on some CEL eliminiators for the rear 02's, you should be able to pass a e-test no problems now... I'm headers + catless + CEl eliminators and I've got no codes besides for an evap that I need to look into eventually...

[Morpheus]

The fist gen exhaust only had 2 cats (primary cat's)
The 1.5gen had 4 cats (primary and secondary cat's)

With both systems, the front o2 sensor is at the manifold, and the second o2 sensor is behind the primary cat's

The secondary cat's just scavenge the left over exhaust to make the exhaust emissions a little better, ie: 1.5gen

The secondary cat's in the 1.5gen are not monitored by the ECM at all.

With both vehicles, installing headers eliminates the primary cat's.

With the 1.0gen, you are left with no cat's, which technically is against the law as far as the Highway Traffic Act.
With the 1.5gen, you are left with just secondary cat's. They don't actually make the tailpipe emissions significantly better.

However, since you technically do have cat's installed on the truck, you are no longer breaking the law, and on a drive clean inspection you do have catalytic converters.

This is your exhaust system Scott:



This is my exhaust system:



My system doesn't tell me if they are the same size, etc.. but you could do some measuring between a 1.0 / 1.5 gen to see if they are the same length. I would suspect they are.

The only spot that may give you some difficulty is that 1 system has a slip fit/clamp system, the other has a flange/gasket/bolt in system

[Scotto]

My truck is now all flang/gasket/bolt. So I suspect my solution to getting legal is using the secondary cats from a 1.5 Gen. Thanks Mike - good info.


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[Miner]

Good post Morpheus!

[Morpheus]

Maybe you can find someone that's parting one out, or turning one into a trailer that you could get the parts.

You can't buy catalytic converters from the wreckers, they won't sell them.

I can price you new ones if you're curious.

[Snafu]

There are two types of magnaflows...I think it was them. One version is code with HM and had more heavy metals and should last longer. When I was getting the exhaust done on the fronty I was shown the two versions. One was definitely heavier than the other and cost more.

The ultimate plan was to add a new cat right at the header flange and add a bung right after the cat for the second O2 sensor. The first O2 sensor is by the flange on the header. The sensors would then measure pre and post cats as it would in a stock system (albeit the cats are further away from stock).

There are the CEL eliminators which were suppose to eliminate the code. I still had the light on but I think this was due to bad primary O2 sensors.

[Scotto]

I don't have any codes from the lack of cats. Weird but true. I just want something that makes it a little more legal in Ontario. Check the cost Mike, but I suspect not -Nissan will be a lot cheaper.


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[Adam]

Here's an idea of what aftermarkets would cost:

http://www.rockauto.com/catalog/raframe ... ttype=5808

[Morpheus]

Club discounted price $580+tax each

There are 2 main types of catalytic converters. Two way and three way. This is why you're seeing different prices on magnaflows.

You need to make sure you put in the 3 way cat, if you really want to be legal.

2 way cat's don't do anything for the main gas they used to test for in the sniffer e-test, NOx only 3 way cat's do.

Here's a clip from the walker exhaust site: http://www.walkerexhaust.com/support/un ... -converter

TWO-WAY CATALYTIC CONVERTERS
Allows oxidation of CO (Carbon Monoxide) to less-harmful CO2 (Carbon Dioxide)
Allows oxidation of HC (Unburned Hydrocarbons) to CO2 (Carbon Dioxide) and H2O (Water)

In this design, exhaust gases are directed to flow through the substrate containing precious metals platinum and palladium, which allow the chemical reaction to occur. The exhaust gases increase in temperature as the conversion process takes place.

Because of the intense heat created by this process, exhaust gases leaving the converter should be hotter than the gases entering the converter. This also explains why heat shields are required on most units.

Two-way converters operate relatively efficiently with a lean fuel mixture. Ineffectiveness in controlling NOx led to the introduction of three-way converters.

THREE-WAY CATALYTIC CONVERTERS
Allows reduction of NOx (Nitrogen Oxides) to N2 (Nitrogen) and O2 (Oxygen)
Allows oxidation of CO (Carbon Monoxide) to less-harmful CO2 (Carbon Dioxide)
Allows oxidation of HC (Unburned Hydrocarbons) to CO2 (Carbon Dioxide) and H2O (Water)

Three-way converters have been used in vehicle emissions control systems in North America - and many other countries - since 1981.

The three-way without air uses advanced catalyst chemistry to store and release O2, in conjunction with an O2 monitoring and control system.

This system utilizes one or more O2 sensors to oscillate the fuel mixture between lean and rich conditions. This oscillation, combined with the O2 storage and release on the catalyst surface, allows for optimum reduction of all three emissions.

Three-way converters are used in conjunction with OBDII diagnostic systems on today's vehicles. This system alerts the driver when the converter is not working at peak efficiency.

[Jayman]

Believe it or not, I still have my stock secondaries sitting in my garage if you want them... I have the stock primaries as well, but they were so plugged up from running rich for a long time that they are next to useless.

I've been hanging on to them because at one point I had planned to take them to a metal recycling facility, but i've just never gotten around to it.

[Nd4SpdSe]

Believe it or not, I still have my stock secondaries sitting in my garage if you want them... I have the stock primaries as well, but they were so plugged up from running rich for a long time that they are next to useless.

I've been hanging on to them because at one point I had planned to take them to a metal recycling facility, but i've just never gotten around to it.

He's got the cheaters. If anything, he hollows them out. It's not ideal because of the expansion of the gases in the cavity of the catalytic converter would reduce performance (may not much different over a real cat), but at the sake of being legal.

If I would of known, I would of kept them intact from the Frontier, but the flanges are too far gone, I sacrificed the cats to save the headers.

[Scotto]

Ok Jayman. You got a deal. I want your old cats.


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[Scotto]

And for Mike, it's not much about being legal as appearing legal.


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