catalytic converter

s2dglt · Post by **s2dglt** » 25 Apr 2012, 19:23

I live in a county that doesn't do any type of emissions, I am wondering if the things I hear about removing the catalytic converter and gaining power are true.
If so, how significant would it be and would if negatively affect my performance.
I have a 95 850 GLT with 206k, completely stock.

Post by **jblackburn** » 25 Apr 2012, 19:27

Yes, performance gains are absolutely true.

Even better would be putting on a free-flowing muffler as well.

Not sure what the power gains are with one of these cars, but you'll definitely feel it. 70s and 80s pollution control systems sucked all of the life out of cars even with huge engines.

If you have an 850 with a rear o2 sensor (some don't have it), you will have to find a method to trick the sensor so it doesn't illuminate the check engine light. There are several methods, from a spacer to an ECU reprogramming.

echase76 · Post by **echase76** » 25 Apr 2012, 20:59

If you are going to put in a free-flow muffler you might also look into a larger downpipe and exhaust piping to maximize the gain.

Realize that depending on how far you go modifying your exhaust you might end up with some drone.

Not sure what you want to spend. I have a 3" OBX turbo back setup with a freeflow cat (needed in my part of PA). OBX exhaust is reasonably priced. Not sure of fitment on an 850? Plus I hear they are back ordered at the moment.

You should go talk to a custom exhaust shop in your area for ideas if you have some $$ to spend. If not, just take out the cat.

Gubernaculum · Post by **Gubernaculum** » 26 Apr 2012, 07:10

I don't think any power gains would be worth the cost and the devaluation of your car - you could never sell it to anybody out of town. Plus I'm not a huge greenie but I can't justify removing a cat unless it's clogged or something and you can't afford the $$$ for a new one.

echase76 · Post by **echase76** » 26 Apr 2012, 20:36

A magnaflow high flow cat will also get you gains and keep the air cleaner. Plus the stink of no cat drove me nuts. Cat plus welding cost me $150.

If you really want to see the gain from no/high flow cat then you need a bigger downpipe to open up the flow.

s2dglt · Post by **s2dglt** » 04 Jul 2012, 16:05

What would be some of the symptoms of a clogged catalytic converter?

Post by **FlyingVolvo** » 04 Jul 2012, 16:15

Catalytic converters were invented for a reason. If you give even a shred of care about air pollution, please consider at least replacing it with a high-flow converter as some have suggested.

Post by **rspi** » 04 Jul 2012, 16:48

What power do you expect to gain with a NA car? Sell it and but a turbo.

s2dglt · Post by **s2dglt** » 04 Jul 2012, 17:56

I'm not necessarily trying to gain power, here lately my car has been smoking if I go in a store and leave it running.
When it sits idling, and I go to back up, it shoots out a puff of white smoke.
I was just wondering if my converter might be clogged.

byeboy · Post by **byeboy** » 04 Jul 2012, 18:22

Do (or have done by a trusted small repair shop) a compression test, That will tell you if you have any one cylinder out of balance (compression wise) with the others. White smoke can be oil or coolant..have you checked your coolant level on the plastic bottle? Is there any sign of water or coolant on your dip stick/

You could just have worn motor, or it could be valve guide seals allowing oil to get in your cylinders.
Start with the free and simple level checks, then to the compression test. the shop will advise you if those numbers are "too low".

If your converter was getting clogged, you would find the car running rich (black smoke).

If you simply want to remove your converter (Federal Offense, but I think they only go after shops) ebay probably has a "Off Road Test Pipe" (Nudge, Nudge, Wink, Wink) fairly reasonable. Let us know your before and after MPG, etc....but it sounds like you may have aworn engine. Have you been keeping up with oil/filter changes? How many miles on the car?