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prwlyn	If you've removed your cats, what did you do about the O2 sensors before and after the cats? I've gotten a couple of ideas from some "racer" types at the office but I'm curious what a Prowler owner has done to compensate. ------------------ Fred J. Henkel "My Kitty's bottle fed!" http://www.lordofthelooks.com
jd2ksilver	Fred, read your email ------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month
Mike Krehel	Fred, Just leave the O2 sensors where they are. I have two cars that are catless and have never had any problems with the stock ECU setting the check engine light. BTW, I've also had both cars pass the DPTS emission test with the cats off. I believe the hydrocarbon limit is somewhere near 240PPM, and the catless car comes in around 100PPM. PS... Sorry I didn't get back on your earlier email. ------------------ Mike Krehel ProwlerOnline.com Click and see me go! Watch me light em up!
prwlyn	Ok guys, I looked at the setup and when I say "removal of the cats" I'm meaning taking them off completely. I'm replacing them with custom made straight pipes into a "Y" flapper valve. This means that the sensors would be just "hanging" down in the air.. Did you only "gut" the existing container and keep the pipe as is? I'll get back under there this weekend and take a closer look but I thought the sensors were in the cat pipe itself... I'm having to have custom made because of the way I'm hooking things up under there. We're having to come right off the manifold with a down turn. We're talking about cutting the manifold side flange off the cats so we have a stock connection at the manifold. Maybe I'm looking at this wrong?? ------------------ Fred J. Henkel "My Kitty's bottle fed!" http://www.lordofthelooks.com
jd2ksilver	Fred I have my car catless completely, not gutted. I have the whole exhaust system flanged so I can run mutilple set ups, differnt mufflers, no mufflers, etc. The headers already have one O2 Sensor fitting. The pipes below where the cats use to be is also flanged so I can put the cats back on anytime I want. That is the pipe (below where the cats would go) that has the the second O2 Sensor. So they are always on the car, just catless at times. Hope this makes sense. I ran a thread on it, and will find and paste, but the pics are gone from it now I think. John ------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month
jd2ksilver	Here it is, I will try to find the pics, use to be on Dans site I think ------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month This message has been edited by jd2ksilver on 10-19-2001 at 01:05 PM
jd2ksilver	oppsss here it is http://www.prowleronline.com/ubb/Forum9/HTML/000076.html ------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month
prwlyn	John, thanks. I did get your e-mail, I didn't mean for you to ???? ???, you know. I think I have a picture of what your talking about and I'll check that out tomorrow. I just talked to Mike and he also explained the way he did it but he "gutted" the existing cats. I'll see which way I'll go but at least the two of you have given me some other ideas. Thanks a lot. ------------------ Fred J. Henkel "My Kitty's bottle fed!" http://www.lordofthelooks.com
jd2ksilver	Ok Fred , but i found them, might as well post. ------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month
Marty Usher	Since you all are talking about removing/gutting the cats, could you tell me if you noticed any decrease in low end performance? I have heard several comments about that result even though it seems to me that without them, there would be less restriction, thus more power, and definitely less heat under the hood. Thanks Marty ------------------ 2000 Black with hand painted blue faded to purple flames
jd2ksilver	It's been so long that I cant remember if the low end is less or more. But as far as heat, at least with mine, no change. I have a supercharger and it still gets way hot under long periode WOT, so I pick and choose when and where now. ------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month
prwlyn	JD, Thanks for the pics, they make it eaiser to show the muffler shop. Marty, from what I hear the cats removal should give about 10 HP to the engine. ------------------ Fred J. Henkel "My Kitty's bottle fed!" http://www.lordofthelooks.com
Mike Krehel	I don't notice any difference in low end performance and the gain is roughly 8-10 HP. ------------------ Mike Krehel ProwlerOnline.com Click and see me go! Watch me light em up!
Marty Usher	John, Fred, Mike Thanks for your replies. Rebecca & I left for vacation on October 20 - no laptop/email, cell phone turned off - it took a couple of days to not miss the electronics but it sure made vacation enjoyable. Then I left for a two day business trip. Anyway - I wanted you to know I appreciate the information and sorry for the delay in acknowledging your replies. I already have an exhaust guy lined up who will do either, gut or replace; I just need to decide which. John - once I clear all my 115 waiting business emails I will let you and Dan know how much we enjoyed your part of the country. We covered a lot of territory - Mendicino to Big Sur (and a lot of wine in between) Marty ------------------ 2000 Black with hand painted blue faded to purple flames
jd2ksilver	Hey Marty,, I forgot about your trip out. I hope you enjoyed it. Very pretty country where you were at. ------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month
prwlyn	Marty, I spoke with my exhaust guy and he tells me what he will to is about the same as John did but with one exception. He is going to gut the cats and then weld a piece of straight pipe inside the cat. Then put the cat back together and in place. This leaves the cats looking like their there and also doesn't turn on the dash light from the O2 sensors. He says that if you gut the cats you wind up with some turbulents inside the cat chamber, this can cause some slight back pressure. With the pipe in place inside the cat it's just a straight exhaust. ------------------ Fred J. Henkel "My Kitty's bottle fed!" http://www.lordofthelooks.com
jd2ksilver	Why would the O2 sensors warning not come on in this setup?? your not doing anything to burn the extra fuel>>>?? It will still trigger the sensor for not doing its job. I'd re-think that. The reason mine do not come on is because the they are nullified by software. Think about it. There's going to be a time in the future when you will want those cats to work I'd bet. I just put mine back on today in fact. Takes 20 minutes after the car is on the ramps. I need the car quieter at times. And, without the cats, you will definitely notice a increase in sound. I also think you will restrick air flow by putting smaller tubes inside your cat, they would have to be smaller than the stock size of you pipes. I could be way off here ,, it is only my opinion... ------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month This message has been edited by jd2ksilver on 11-02-2001 at 02:34 AM
Marty Usher	Fred - that is actually what the guy was going to do on the gutting cats option - put a pipe through it. If what John says is correct about having to use a smaller pipe inside and the fact that my exhaust is already only 2 1/4 ", I may have to think more about it. Our city/state emissions testing standard here is 220 PPM so according to MikeK's reading of 100 I should be OK without cats totally. They are considering a statute to change testing to include visual inspection of cats. If it really isn't a huge hassle to reinstall once a year for inspection, I may go that way. Thanks everyone for all the input. Marty ------------------ 2000 Black with hand painted blue faded to purple flames This message has been edited by Marty Usher on 11-02-2001 at 06:56 AM
jd2ksilver	Marty, what are you doing to prevent the check light from coming on for the O2 sensors? Just curious,, ------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month
Marty Usher	John - until I saw this thread I didn't realize I had to do anything. I see where Mike says his doesn't come on. I'll have to ask my exhaust guy if he has any suggestions. I am assuming the software you are using is part of a engine management system controlling your SC? Worse case is I go back to what I use to do in my youth and remove the bulb from the dash or learn to ignore it. BTW - your photos are great. I have printed them to show how the system looks when you replace the cats totally with pipe. Thanks Marty ------------------ 2000 Black with hand painted blue faded to purple flames
jd2ksilver	------------------ See me WAX a Roush See me WAX a Cobra CAR & DRIVER of The Month
prwlyn	John, I'm not the expert but As mentioned Mike did the cat gutting and put them back on and the light does not come on. I spoke to one of the "racer types" at my office and he says he did the same thing to his Honda and no light. If it comes on I'll fess up.... ------------------ Fred J. Henkel "My Kitty's bottle fed!" http://www.lordofthelooks.com
jd2ksilver	Your guy is probably right Fred. Go for it. New ideas is what it's all about.
prwlyn	Thanks John. The first part of my exhaust plans is complete... My Chrome Lakes pipes are installed as of today.. Hopefully will get pictures up tomorrow.. What a finishing touch to a great looking car!! ------------------ Fred J. Henkel "My Kitty's bottle fed!" http://www.lordofthelooks.com