[flash]

there are only 3 aftermarket companies that make CARB certified cats, though they sell them under a number of names. none of them are good enough for california emissions on the 968, even though they are listed for it. the way it works is that you get a cat certified for a particular engine. then it gets grandfathered into application for any other engine of similar year and size. that does not mean that it will pass the tests on your car. it only means that the design parameters are similar enough to be cross-applied to a different engine. i had a very long conversation about this with the people that do the testing, as well as CARB. it is a real problem with no real solutions. the way they deal with it is to require you to spend a bunch of money attempting to correct things, and then when it still fails, they grant you a pass.



back when i was running the header, i played with a few different cats. no go. also, they ALL resulted in power loss, with the high flow ones losing the most down low. it was bad enough that the header cost me low end, but the cat made it really mushy. the only way i could get anything to pass was to use a huge double biscuit cat, and get it REALLY hot. then, it passed right at the upper limit. in the end, i put back in the OEM cat and flew by the tests. ultimately i removed the header and put back in a modified OEM header and gained back nearly everything the aftermarket header gave me, and without the low end loss.



back on topic, cat contamination is a huge problem. worse than ZDDP levels, running rich will do it in a hurry. some of the chips that are out there run way too rich (including ones from the above mentioned "guru"). this is especially true if you disable the O2 sensor. it will shorten the lifespan of the cat significantly, which will be a real problem, as they are no longer available. on a race car (not to be confused with a DE car), where you remove the cat anyway, this is not an issue. but on a street car, and especially where you have to undergo testing (which is increasing area by area year by year due to increased population) this could be the difference between being able to drive the car and not.



as for ZDDP contamination, i don't have any data to say how much is too much. i wish there were more information about this.

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[968cabx2]

Flash,



This is going to go off topic but I would hope you would elaborate on a couple of the things you mentioned in your post.



I was running a FR Wilk power prom in my 968 tip. It had ok performance gains over the factory setup and I was getting about 22-23 miles per gallon. I record every fill up so I know my mpg almost exactly for each tank. I then switched to an RS Barn stage 1 chip and felt a marked performance improvement over the FR Wilk chip and am now getting 25 to 27 mpg. Needless to say I was pretty impressed. This is why I was a bit shocked when you said that the RSB chips run rich. Last thing I want to do is intentionally destroy my cat by running rich. I know you were working on a chip for the tips which I am eagerly dying to try, but in the mean time can you elaborate a little on what you know about the RSB stage 1 chip and it's characteristics. Do you know that the chip disables the O2 sensor, and if so do you know if the Wilk one does so. Just would like to hear a bit more about the damage we might be unknowingly doing. Thanks

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[flash]

we need to have that discussion in a separate thread, not this one. you are making a lot of blanket assumptions that deserve discussion. for example, both of the chip brands you mention come from guys who make a lot of different chips for different uses. it's not one size fits all.



again, a discussion for a different thread, in the chips and salsa area. start a thread there and i can elaborate.

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[Ernie]

So, I hope this is on topic, and is directed to Flash. Many of us eagerly await the suggestions/design you may have to get that extra 35hp. My question is this, does your exhaust reqiure some sort of aftermarket cat, or do we need to "save" ours? I mean if the ZDDP saves our engines, but kills our cats, if we go with a different setup maybe we spare our engines? Right or wrong?

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[flash]

i have always been an advocate of retaining the OME cat. it flows better than most people think, and better than most aftermarket cats. my mod retains the OEM cat. there is no indication that the levels of ZDDP in the original synthetic oil would cause premature failure. the cats on our cars are designed to run 100k miles.



unfortunately there is no quantitative data i can find regarding the levels of ZDDP in various oils, and how they stack up against each other, or what that means on a precious metals cat (like ours), versus a ceramic cat (like the aftermarket ones) both of which behave very differently, and have very different life expectancies. a ceramic cat only has a 60k mile life expectancy. it is also far more subject to failure from contamination.

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[ryker]

I had the cat replaced in my Blue '94 at a shop in Sacramento with a Magnaflow. $245 installed. It passed CA smog the same day.

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[ds968]

[quote name='ryker' timestamp='1403032223' post='158682']I had the cat replaced in my Blue '94 at a shop in Sacramento with a Magnaflow. $245 installed. It passed CA smog the same day.[/quote]



Wow, holy s**t, that's GREAT news !

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[flash]

lol - i used what was most likely the same magnaflow unit. passed, but barely. could easily be the probe that varies. dirty probe, easier to pass. this is one where you should probably seek out the nastiest and/or busiest station around.

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