Exhaust A Pair Of Bassani 25msc Catalytic Converters Will Pass California Smog

[Chythar]

This post is for anyone doing a StangNet or Google search, wondering if the Bassani 25MSC cats will allow your 1995 Mustang GT to pass California smog tests. As my GT passed the test not 10 minutes ago, I can tell you that they will. I added the Bassani cats to an off-road Bassani x-pipe, so they are the only cats on the car. The engine is 100% stock at this time. I didn't use any additives in the tank or any other tricks.

EDIT 7/28/12: Two catalytic converters no longer pass California smog. California set new rules for manual transmission cars: the car must be in 1st gear during the 15mph test, and in 2nd during the 25mph test. With two cats and these test changes, I just barely failed. Later post shows my test results.

Here are the emission test results, as of 9/12/10:

15 mph: HC MAX: 59 AVE: 20 MEAS: 58
25 mph: HC MAX: 34 AVE: 13 MEAS: 34

15 mph: CO% MAX: 0.34 AVE: 0.00 MEAS: 0.02
25 mph: CO% MAX: 0.32 AVE: 0.01 MEAS: 0.02

15 mph: NO MAX: 484 AVE: 231 MEAS: 154
25 mph: NO MAX: 498 AVE: 232 MEAS: 332

Now, I did just barely pass the HC test. But this is with one catalytic converter per side instead of two. Not bad for newer technology. Be aware that California just recently tightened the emissions standards on all cars; the max allowed is lower than the last time I was tested. If you passed on your last test, you may not pass this time because of the higher standards. Looking back on my last smog test, where I still had the stock h-pipe and cats, I would have failed the test this time.

The Bassani cats are of a honeycomb design on the inside, they let the exhaust flow freely past without restricting it like the OEM cats do. I did notice the exhaust was somewhat quieter with the new cats on, but not by much. I didn't notice any difference in the exhaust tone, just the volume.

 

[Adam95GT]

Nice work man. Gives me hope for tuesday

 

[HISSIN50]

It's nice that they don't fail you for having fewer cat housings than came on the car originally.

 

[Chythar]

It's nice that they don't fail you for having fewer cat housings than came on the car originally.

SHHH!! Technically, yes that should fail the visual inspection. But no one knows how many cats each car is supposed to have, so all the shops check for is that you have cats. Technically, it's even illegal to change out the midpipe - one is "not allowed" to put any emissions parts on that are not non-OEM or OEM equivalent. But again, no shop knows what each car had on it from the factory so they don't really check.

I like to think I'm sticking with the spirit of the law, rather than the details.

 

[Adam95GT]

SHHH!! Technically, yes that should fail the visual inspection. But no one knows how many cats each car is supposed to have, so all the shops check for is that you have cats. Technically, it's even illegal to change out the midpipe - one is "not allowed" to put any emissions parts on that are not non-OEM or OEM equivalent. But again, no shop knows what each car had on it from the factory so they don't really check.

I like to think I'm sticking with the spirit of the law, rather than the details.

I hate people that dont run cats... Bad for the environment and smells like crap.

 

[HISSIN50]

I'm with you and your interpretation.

 

[Chythar]

UPDATE - two Bassani cats will NOT pass CA smog anymore. California set new rules for manual transmission cars: the car must be in 1st gear during the 15mph test, and in 2nd during the 25mph test. With two cats and these test changes, I just barely failed. Here are the emission test results, as of 7/21/12:

15 mph: HC MAX: 59 AVE: 20 MEAS: 62
25 mph: HC MAX: 34 AVE: 13 MEAS: 39

15 mph: CO% MAX: 0.34 AVE: 0.00 MEAS: 0.04
25 mph: CO% MAX: 0.32 AVE: 0.01 MEAS: 0.05

15 mph: NO MAX: 484 AVE: 231 MEAS: 152
25 mph: NO MAX: 498 AVE: 232 MEAS: 360

I'm sure there are plenty of tricks to lower my emissions for the test, but I prefer making changes ONCE. So, I put on two more Bassani cats. What I have now is essentially a Bassani catted X with two more cats; part number #25MSC.

 

[revhead347]

It's more of a matter of tuning that cats. Some cars do well, others don't. My buddy's Cobra is basically stock, and has trouble passing every year. My car has a huge engine, and puts almost no emissions. It actually does fine without any cats. I have no idea what causes the problems in some cars.

Kurt

 

[Chythar]

UPDATE - While four Bassani cats still pass the California sniffer test, there's a new visual test that the tester has to do. They look for a serial number on the catalytic converters, and compare it to a list. If the numbers don't match, you fail. From what I was told, there are now random inspections on the roads, and all they really do is a visual inspection. If you fail this test, the last shop that passed you can lose their license.

However, all the info I can find is that these random inspections are considered to be surveys and are optional. The cops running them imply they're required, tho.