Catalytic converters removed?

Terry Holtz · 12-11-04, 09:17 AM

Hello... I would like to hear from C-5 owners their experiances in removing their cats. Weight savings? HP gains? Did it pop codes?

Anyone?

Ken Anderson · 12-11-04, 06:38 PM

BAD IDEA for a street car!

TODD L GRIFFITH · 12-11-04, 06:53 PM

The cats removed will definitely throw a code. The need for 02 simulators would be needed to be installed. The expected hp gain would be approx. 5hp. Not really worth doing. In addition, the vehicle may fail the next emissions inspection. You are better off installing high flow cats.

Terry Holtz · 12-12-04, 05:45 PM

>>>>>>The cats removed will definitely throw a code. The need for 02 simulators would be needed to be installed.<<<<<

Would the o2 simulators stop the code from coming up? Thanks for your reply

TODD L GRIFFITH · 12-12-04, 07:18 PM

Yes, the O2 simulators would trick the PCM into thinking that the cats were still installed by producing a .450mv signal back to the computer. The simulators are to go in place of the rear O2 sensors behind the cats. The simulators can be purchased through Mid America for about $150.00. The link to the online catalog is www.madirect.com .

c4c5specialist · 12-14-04, 06:10 AM

HI there,
The BAD side to simulators, is that this will throw off your fuel trim calculations.
Do NOT expect that there will NOT be issues with how your vehicle runs with the simulators in your car.
Just a word of caution, because not everyone wants to LS1 edit for a couple hours to forge calibrations.
Allthebest, c4c5

TODD L GRIFFITH · 12-14-04, 07:07 AM

Good point c4c5. I would not recommend removing the cats completely. Additional tuning will be needed. LS1 edit or a hand held programmer with good capability like the $420.00 Pedator is not too cheap on top of simulators just looking for a few ponies. I'm not sure if Terry has done this already or not. Have you already removed them, or just thinking about it?

Terry Holtz · 12-14-04, 08:50 AM

I have not done it. Just thinking about it. I have heard the cons, but was hoping to hear some good news from the other side. If they never post, as it looks like, then I suppose I will blow the bank on stainless long tubes, hi-flow cats, and titanium rear exhaust. Any recomendations? Realistically, how much torque and HP gain should I expect? weight savings?

Are hi-flow cats really hi-flow? Why didn't Chevy put them on in the first place, at least for the zo6's?

Perhaps the people who sell the O2 simulators should give notice of the fuel trim calculations problem. They never seem to mention the problem in their ads.

Thanks, Todd and C4C5.

Remo · 12-14-04, 03:25 PM

Terry,

Put some hi-flow cats on it, a Corsa X-Pipe, a Borla Stinger exhaust system and call it a day. The exhaust will flow smoother, you'll get a few more ponies and the car will sound sweet.

Remo

c4c5specialist · 12-15-04, 06:14 AM

HI there,
Personally, from a technical point of view, every aftermarket cat system I have seen may throw a code at one time or another.
I have found, so far that Kooks headers and converters system have been the best overall as far as power, emissions worthiness and quality.
It takes me about 6 hours to install, but worth it in my opinion.
Allthebest, c4c5

DarkShark · 12-15-04, 07:46 AM

I agree with C4C5. If you are looking for more power- run high flow cats and low back-pressure exhaust. You need some back pressure. Use the cats to get it. They will help optimize the air/fuel ratio and ensure you have the most power for your vette.

Terry Holtz · 12-15-04, 07:49 PM

>>>>>>Kooks headers and converters system have been the best overall as far as power, emissions worthiness and quality.<<<<<

Are Kooks long tube headers stainless? And after the high flow cats, I'd like to go titanium, so that if nothing else, I've made my car a little lighter! By the end of February, I will either get hi-dollar brakes... or an exhaust system.

Terry Holtz · 12-15-04, 07:52 PM

>>>>>>>Put some hi-flow cats on it, a Corsa X-Pipe, a Borla Stinger exhaust system and call it a day.<<<<<

Remo, you don't think long tube headers make much difference?

TODD L GRIFFITH · 12-15-04, 08:22 PM

You could possibly see 25hp extra from long tube according to my ls1/ls6 performance engine build manual based on a ls1 with long tube headers, high flow cats and a performance intake. Not too bad of a gain. The removal of the cats is not worth the small gain you would receive +/-5hp. After buying O2 simulators and reprogramming, you would have atleast half the money spent towards a long tube header system anyway. I like the deal with the Supermaxx system. $1499.00 for long tube headers, high flow cats and x-pipe. On my old 99 hardtop, I spent around $2000.00 before this supermaxx system was available. http://www.rpmoutlet.com/c5hits.htm this link has a nice deal too for $1295.00. I didn't really read it to see if the high flow cats were included, but the $1499.00 system has it all from http://www.madvet.com/shop?part=1.5778.618543 I'm thinking about the supermaxx system for my ZO6 at those prices.

c4c5specialist · 12-16-04, 05:04 AM

Quote:

Originally Posted by Terry Holtz

>>>>>>Kooks headers and converters system have been the best overall as far as power, emissions worthiness and quality.<<<<<

Are Kooks long tube headers stainless? And after the high flow cats, I'd like to go titanium, so that if nothing else, I've made my car a little lighter! By the end of February, I will either get hi-dollar brakes... or an exhaust system.

HI there,
Yes, the complete system is stainless, headers, connection pipe, cats, and x pipe.
Light, could be, but I have not weighed them.
Allthebest, c4c5