Lemon Yellow 87 n/a

I'm planning on installing a straight pipe in place of my cat. I do not know whether or not the cat is the problem but under hard acceleration, I can hear a ringing/resonance coming from the cat along with (I am not sure, I could be paranoid) what I suspect is a miniscule loss in power (so small or maybe inexistant that I usually dont notice it). I dont know what it is. Speed climbs steadily as do revs. There acppears to be no visual connection between the noise and performance. I have been told to replace my o2 sensor, but I dont think it has hold over the mixture under hard accel. Also, Maybe the fuel mixture needs to be adjusted (which I was also told could be the prob). Furthermore, what on earth are knock sensors, are they for pinging/detonation (no, I dont have pinging)? Everyone seems to know what they are except for me. Any advice would be much appreciated.

-Matt

jim968

Well, lessee here...

A) The funny noises could just be the exhaust not properly aligned, centered, & tightened in the tunnel, tho' a busted core in the cat will rattle, at least on VW products.

B) Small loss of power could be any of a dozen (other) things, as well.

C) Test pipe in place of cat is OK, maybe good for a couple of HP, more if your cat is clogged. But one, it won't pass sniffer emissions testing, if you have that where you are, or even a strict visual inspection, and two, you'll have absolutely no moral right to bitch about corporate acts of pollution, since you'll be driving your own lil' voluntary fume factory. Also has to be a DIY install, unless you know a real "friendly" shop; a federal bust for them, not you, IIRC.

D) Knock sensor is a piezo (sp?) electric crystal in a housing bolted to or inserted in the side of block; responds to the particular frequency of detonation, sending a signal to the DME (KLR?) brain to retard timing (reduce boost on Turbos??). Found only on S2's, Turbos, & 968's, AFAIK. Not on 8V na's, at least thru my old '88.

This any help?

Jim, toddlin' off to bed... been a long dam' day.

Lemon Yellow 87 n/a

Thanks Jim. I'm definately gonna check things out when I go in for analignment.

Tabor

Jim,

A lot of cars will pass emissions without a CAT. ALL cars must come with a CAT in the US, even if they would have passed without it. I am all for passing emissions, but I don't like technicalites, and this is one.

Brian Wilson

Good call Tabor,
I believe there was a thread maybe a month or more ago about a fellow who got enough advice about things to change on his car to make it pass emissions. They were all just little things that could easily be changed back. Can't remember exactly when it was though.

BTW-emissions, ha ha ha.

Although I can't exactly run nitrous either...

Thaddeus

Emission controls aren't a joke. Just go to a country that doesn't have them-- like Ireland. The air quality sucks, half the people I talked to there complained of chronic asthma.

...Or the US before the Clean Air Act. I remember going to NYC when I was a kid, fell asleep in the car with the window open as we drove through the city... my face was covered with soot on the side near the window when I woke up. Great to breathe.

I am going to test... yes, test... my car with a test pipe but only to see if the performance improvement is enough to justify a less restrictive cat. If the improvement is only a smidgen, I'll just put the cat back on.

Thaddeus

ribs

Do you want to see one pissed off cat? Here is one:



In this picture I imagine the one in the middle is feeling a bit violated:



hehe

I can't sleep! Its been 25 hours and counting, I have layed down 4 seperate times over the course of my insomnia, and I can't get a wink. I am thinking about taking some prescription downers I stole from my dad (he suffers from chronic insomnia) or downing a couple of shots of cheap vodka. Which do you think will do better? Sorry for post whoring, but the title was just asking for it.

aka 951

Welcome to the club ribs...I feel the same way today after pulling an all nighter...can you tell?

Tabor

Alchohol will lead to short, unfulfilling, wrestless sleep.

ribs

If you drink too much, yes, but I find that 2 or 3 drinks an hour or so before I go to bed really helps me get to sleep better and faster, and I sleep very well and fully. I prefer to drink wine before bed though, because if I drink beer, I always feel like having another one after I have had a couple...must be the partying spirit/latent alcoholic in me. Speaking of which, I woke up at 6 PM today after going to bed at 10 AM (no daylight for me...maybe I should start sleeping in a coffin or hanging upside down from the ceiling), so I have been conscious all of 5 hours today. I might want find something that will knock me out so I can fall asleep before sunrise tomorrow...I may just try to drink a couple glasses of wine, or perhaps 1/2 a bottle of nyquil...must make it to the grocery store before midnight...

ribs

Well...I ended up going to the local college bar and having a few beers, and this one chick (quite attractive) was dancing real dirty with me, and she was whispering all this stuff in my ear about going home with her and what she would do to me when we got there and then I had to take a **** and told her not to go anywhere and I came back and she left the bar. . I think I will be able to fall asleep fairly easily though, and I don't have to be up until 12:30 for my 1:00 class (the tough life I live), so I hope to, for once in a week, get a full nights rest. Good night.

Lemon Yellow 87 n/a

Hah Ribs!!! When did this happen? My classes are over for now and I picked this chick up at this rave kinda place. It was friggin COLD outside (car felt like an S2 again) and we wanted to go somewhere private. We were both drunk so I start makin out real nasty with her while she was leaning on the drivers side rear fender (she thinks I'm rich cause I'm 18 and I have a Porsche hehe). So it gets heavy and I cant feel the cold anymore and I start groping her *** (g-string baby). She thought the cold fender was sexy (drunk ***). So I go downstairs to the car-hole (I dont call it a garage anymore) this morning to start prepping the car for its makeover (got pre-claybar solution, clay bar and caranauba wax) and I noticed nice round *** cheek smears on the fender. Looks like I'm really gonna need the clay bar now!
ps, I didnt go all the way with her, I could not drive and I never let anyone drive my car, so I kinda dozed off in the drivers seat, waiting to soberize. Next thing I know, I'm in the passengers seat and my best buddy is driving. Even worse, he said he called a cab for the chick and I didnt even get her number!!!!!!GRRRRRRRRR!!!!!! Suits me right for drinking and having my car with me. We usually have this buddy with a ****ty van who drives all of us and doesnt mind not drinking.

Matt O.

If the cat is pissing you off get a dog. Like me, I'm getting my first German Shepherd puppy this saturday in Raleigh. Wish me luck!

-Matt
Who will not only be the proud owner of a German automobile, but also a fine German dog.

ribs

Ha! Nice story, and nothing beats a perfect ***-mark on your car...I have several sexually frustrating stories where alcohol is in one way or another related to me not getting the hook-up (but I would have never been in the potential hook-up situation had alcohol not been involved). The one I told last night happened about 20 minutes before I wrote it. If I hadn't been drinking, I wouldn't have needed to ****, and I probably would have hooked up with that chick last night, but, things being the way things are, I probably would have never started dancing all nasty with that chick (and I mean nasty...she slid my hand down and I dry goosed her while we were getting freaky in the bathroom line...yes, we were dancing in the bathroom line...it was that kind of a bar) if I hadn't been drinking (catch 22), but, oh well...live and learn...next time, I am going to bring the chick into the men's room with me to make sure she doesn't run off on me.

I'm done with classes today, but have finals friday and monday (I feel bad for the people at my school who have finals next thursday), so, I will probably have to wait until next semester to get more booty from the college girls (home town girls is another story). Does anybody else in college notice that you and everybody you know ends up doing 75% of their hooking up in the first couple weeks of the semester? I wonder why that is. I love college but I hate the academic part...ironic, huh?

Bob Price

howdy all -
my 944S has a knock sensor - the compression ratio on that engine is something like 10.9:1, so Porsche was especially concerned about detonation.

now, concerning rattling cats - the other day I noticed I had a funny rattle at certain rev's coming from somewhere under the car, and the engine wasn't running quite right. turned out the O2 sensor had unscrewed itself, was rattling in its socket, and the fresh air being drawn in past it was confusing the computer into thinking the exhaust was lean, so it bumped the mix way rich. anyhow, that's one more thing to look at while you're knocking around under the car.