Sexy928Porsche

Seems that my cat is causing problems...NYS states that emissions control systems on gas-powered vehicles that have a model year of 1996 and newer have to pass. Nothing about prior to 1996.

So Would there be any problem if I remove it? With the car I mean. And if not, what do I have to get to replace the missing cat (I'm not THAT familiar with the whole exaust system yet! Infact, with any exaust system)!

Any suggestions are appreciated! Thanks!

-Jen

1987 Porsche 928 S4
70,629 miles

=Seems that this car has so many "hidden problems". LOL=

Airflite40

sure! ditch the air pump, cat and get an x-pipe!

FlyingDog

According to federal law, if your car was built with a cat, it needs a cat. Most states have similar laws. I think NYS is a CARB state which means they will make sure it is there during inspection.

That said... my 928 doesn't have a cat and my Jeep only has cats because it is OBDII and under warranty. I have a strong dislike for cats after lighting mine on fire several times and watching people torch their entire cars from cat fires.

BTW, you haven't discovered 1/10th of your car's hidden problems...

figgen

You should be able to have an exhaust shop cut out the cats (remember NO welding while the brain is connected). As mentioned installing an x pipe where your cat was becomes a great option, if not have the shop replace with a straight pipe...my shop stamped my receipt "for race application only" or something like that. The air pump can be removed ( saves weight and removed the hp draw on the crank...not that it is much) and remove the air tube that goes to the cats and viola your cat less. Check your O2 sensor while your in there to ensure your brain is being fed acurate data and you should burn pretty clean anyway.

dr bob

It's hard to believe that NY doesn't care about cars over ten years old. It's the older cars that tend to be the worst polluters. Removing the cat will make the car noisier. It will make the exhaust stink too. Are you thinking about this as a cure for the burning problem you wrote about a few days ago? Consider that the overheating cat is a symptom, not a problem. You have a problem that is causing a lot of unburned fuel to make it to the cat. Cure the problem and the overheated cat symptom will disappear.

Be a good neighbor-- fix the problem, leave the cats in place.

My two sense....

FlyingDog

Since when?

MGW-Fla

yeah I say DITCH THE CATS!!!! I love the environment as much as most people, but common now..... there are much bigger problems than her 928 without the cats. Lord, just this week alone in traffic I've seen several cars pouring out so much smoke you'd think they were on fire! You see them on a regular basis here. If those can slide without recourse, then the system is just messed up. You will notice more low end torque, a more robust exhaust note, and perhaps a bit of gas/exhaust smell upon start up or shut down, but not enough to deter from the added benefits in my book. Again I say, DITCH THE CATS & GET AN XPIPE!

Normy

When you remove the cats, if your car runs rich at all, then it will smell like an old school-bus at stoplights.

-Really, cats only lose you about 3% of your overall power, which results in a performance penalty that is essentially unmeasurable. ONE thing that is peculiar about catalytic converters is that they are susceptible to damage from gasoline, and will melt if the ignition fails and gas is blown into them. That's how cat fires start. That or they get plugged-up and now your car doesn't run right at all.

I'm running without cats right now, but this fall I want to install a pair of Random-Tech cats, which supposedly cost no power up to the 500 hp level. My only concern is that my car sounds so good right now without them!

Figgen- you won't be able to find a shop to remove your cats for you, unless you know the owner personally and he trusts you quite a bit. Shops can be fined hugely if they remove pollution control equipment from a car, and even if they so much as work on a car that has had it's cat's pulled by someone else, they can still receive a stiff fine! He's going to have to be his own exhaust man on this job.

N!

hacker-pschorr

Well, newer fully functional CATS yes - these are 20+ years old. On the 16V US cars they rob a ton of power.

sfierle

My 1983 has not cats (I bought it that way). Has a nice aggressive exhaust note and I haven't notice any exhaust stink.

blown 87

The other 9/10's show up when you are at least 200 miles from your home.

FlyingDog

With or without cats, if your car is running rich, the exhaust smells. Most cats rob WAY more than 3%. My car is completely different without the perfectly clean 3" Catco performance cat that was on my car. The exhaust guy that redid mine was amazed at the difference. Before he cut it off he guaranteed me that the cat had to be clogged with the way it sounded like the exhaust was choking the engine. When he cut it off, we looked through and it looked brand new and completely unclogged.

Of course the performance benefit is secondary to the risk of torching your car, and the air polution reduction when you have one is second to the heavy metals polution from using and disposing of one. I'd rather be safe and have clean drinking water than have marginally cleaner air.

Imo000

That may be in a N/A application, but it makes a HUGE difference when boosted. I’ve removed mine and replaced it with only an H- pipe and the engine woke up. My guess is at least a 25hp gain from removing the original cats. A boosted engine loves free flowing exhaust. The freer the better.

On a N/A car I wouldn’t remove them. If they are plugged, replace it cause as mentioned above the gain is hardly noticeable but the smell sure isn’t.

SMTCapeCod

Some information from Random Tech was posted to a similar thread on a jeep board that I visit. Scary if they're 'greener' than us!

SteveG

I can say that NYS does care and you must have a special relationship with this shop. Or the locals in your area may have some grandfathered release letting small shops off, it was that way in PA when emissions testing was introduced just a couple years ago. Depending on the location a small shop that would have suffered severe cash flow problems due to the expense are exempted. BUT to say "NYS doesn't" is incorrect.

If this shop sells or for some reason you can't use them anymore, you could have a problem, and/or selling the car outside this area could be a problem. I thought I would never sell my '85, but things change and as soon as the new cats are in place, I will be listing it. I think the 3% figure is close and if that bothers you, there are high flow cats with or w/o an H pipe offered by 928 Motorsports SLC who are well known here.