Eliminate "Cats" On '95 GM?

[miamibob]

Not sure if my cats have any adverse issues but it has factory dual exhausts so has four cats. Can any of them be eliminated (straight pipes) or do they need to have replacments? Since it has four O2 sensors (two before the cats and two after) it is an interesting question. By the way, not sure if this is in the proper section.....Bobby

P.S. What is the proper way to find if the cats have issues (any form of blockages)???

[gadget73]

Legally, no. Federal emissions standards, blah blah blah. If its got 4 oxy sensors, then it will set a check engine light unless you get the MIL eliminators.

Cats last a really long time unless the motor burns oil or whatever. The usual check is a backpressure test. Basically they hook a pressure gauge up to see if there is a restriction in the exhaust.

[slymer]

you could put on some magnaflow direct bolt-on cats (that'll be $300 though) and be assured that there's no restrictions... or just run it till it dies.

[90ltd]

I had a 95 TC it had precats (the forward ones) only and it passed tailpipe emissions with flying colors. On it I noticed that somebody moved downstream O2 sensors about 2 feet further down (i guess it read cooler because mil never came on).

[SVT98t]

I gutted my cats, unplugged the O2 sensors, and removed the CEL bulb. But I would not recommed doing that.

-ryan s.

[Crownvicman289]

I gutted my cats, unplugged the O2 sensors, and removed the CEL bulb. But I would not recommed doing that.

-ryan s.

Only thing I don't like about that is you lose the CEL function for other stuff that you might actually care about. Just chop out the back 2 and call it a day. Unless you're trying to pass a visual, I don't recommend gutting cats. The expansion chamber creates turbulence and is more restrictive than a not plugged cat. I have a gutted cat for my Corolla, but it has a 2.5" pipe welded inside of it, so it's seamless.

[88Vic]

I don't know where you'd get a MIL eliminator like gadget suggested but if those are cheap then I suggest that. If not you can get Thunderbolt cats for about $40 each on Performance-Curve or ebay. I have one on my truck and it doesn't quiet the exhaust at all and it's not restrictive at all, in fact lost low end since it flows so well, but running 3" exhaust on an old stock 305 is what killed it.

[phayzer5]

I don't know where you'd get a MIL eliminator like gadget suggested but if those are cheap then I suggest that.

Look at any place that sells mustang performance goodies, mail order (Summit, Jegs, etc...) included

[slymer]

95 shouldn't have rear oxy sensors unless it's a very late 95 with the 96 electronics. Shouldn't need mil eliminators for cat removal.

[miamibob]

According to the Build Sheet it was built 12/16/1994. Does that help?? It has 4 O2 sensors. Took me long enough to get them installed (plugging into their harness' so I know for sure). Bobby

[slymer]

wow... I didn't think they put that on the 95s... I guess they did.

http://www.latemodelrestoration.com/Product/Search?q=mil%20eliminators

[Lincolnmania]

yea my 95 thunderbird was obd2

[johnunit]

OBD2 was kinda like the switch to R134, they had to be in by 1996 but some adopted earlier as part of a larger update.

[miamibob]

Yep, my '95 has 4 O2 sensors and R134a standard.

[slymer]

my 93 came with neither... though has 134a. No r-12 in anything I own any more.

[miamibob]

Yeah, my Dad's '93 had R-12 but since it was colder than the Artic in January I left it alone.

[BigMerc96]

Even on the cars with 4 o2 sensors (which you '95 should have), the rear '02 sensors are between the first and 2nd cats, meaning they only actually monitor the first cats. If you follow the logic here, that means you can remove the rear cats on both sides, and the car won't know the difference. Its something I've been thinking of doing myself.

[LimitedStreet]

Guess it all depends, do you have to pass emissions in FL with a 1995 model year car? Where I live, 97 and older no longer has to pass emissions, so anything I own 97- gets the no cat treatment :D You probably wont notice much power difference unless your cats are blocked pretty bad. Of course, I wont be running cats on my '03 but between the tune and some appearance modification I'm going to try a couple creative things to pass :). Not that I'd suggest you do that.

[miamibob]

No emissions test anymore in FL but for the present will leave it be.