High flow Cat life ??

SuperCoupeSC91

Registered User
I just had a really bad night..I just beat a Jetta i think VR6, and went to the gas station, gased up, then as i left the gas station i herd something underneith was rattleing (middle of my car, i was scared), a little bad, drove slow after i herd the noise, got home took out the mag light, then didnt see anything, then i started to kick my exhaust and i herd a little dinging of loose particals inside, now i'm pissed was just going to go out to the pike to drive around and see all the other cool cars, nope home now....AHHH....anyone know how long a high flow Cat from SCP is suposed to last ??? mine only has like 6-7k on them...dam.....
 
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i just installed my 180 thermostat and had my coolign fan hardwired and was just finally running at 200 degrees, i remember a while back when i bought a 180 thermostat from napa the guy told me "i dont recomend this , you will clog your cats in 6 months.." i was like sure ok not worried...well i switched back but now i had 180 put back in and hardwired fan and finally running at 200 degrees ? is this why my cat blew out ??
Alex LaChance

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hmmm

i don tknow why a 180 t stat would clog up your cats.... im also very interested to hear the diagnosis on this one....
-damon
 
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i think i remember the guy telling me my car would be running alot richer because it wouldnt be getting up to factory tunned specs for the computer, said when its cold its richer, then when it gets hot it get leaner..something like that i think...Alex LaChance
 
well

well id love to hear some other opinions on this... but personally that doesnt sound right to me. the 180 t stat doesnt even really make it run that much cooler,, for some it does but not enough to make it run like the mechanic said... for some people it doesnt even help at all. but maybe im wrong, Someone else jump in.... im so curious about this now... it just doesnt sound right to me. I have a 180 t stat in my car, with no probs..
-damon
 
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o run so much cooler now with a 180 t-stat and hardwired fan that i always have one, i didnt notice before a difference when i had just the 180 t-stat but now since i hardwired my fan, what a difference.... 180 on a cool day, 200 tops on hot day, and 210 with gettin on it....i used to hit about 230 before with my mods..
 
oh yea

oh yea, with the fan mod and t stat it makes a great diff, i dont have the fan mod. i just unplug my AC compressor and then put on the MAX AC switch whenever i want the fan to come on, so it's almost the same, and yea it runs around the "n" all the tiem around town. but i just dont see how that would make u run rich, ive never read or heard about that happeneing before, like i said hopefully we'll get some people to jump in and correct me if im wrong.. or tell me im right :D i really dont know-
Damon
 
Of course lower engine temps make your engine run richer. The fuel and timing tables in the comp are set up and related to engine temps as well as a few other things.
Engine temps are what controls the extremely rich mixtures needed for cold engine startup, it works just like a choke on a carbed motor.:)
 
i Had the same problem a couple years ago with the scp high flow cats--mine lasted about 5k and they offered no warranty

after researching those cats a little I found that they are a low quality item and they are really not the appropriate size\design for the sc
any way tough to find out the hard way
maybe try a good set of catco's if u wanna keep cats
g/l
Josh
 
You said you've been running at 200 degrees, so this cat problem probably isn't related to the 180 degree thermostat.

(Note - a 180 degree thermostat won't make a car run any cooler unless the cooling system has the capacity to keep the coolant at 180 degrees. On an SC, the lousy stock cooling system is BARELY adequate for the stock 195 tstat, and no way could it keep the coolant at 180. So I wouldn't worry about that causing the car to run too rich. But I also wouldn't waste my money on a 180 degree tstat...)

Cats don't just "wear out". The catalysts are coated on a ceramic substrate, and by definition a catalyst is not consumed in the chemical reaction. So any cats should last a very very long time on a properly running engine.

But what ruins cats is: physical damage from debris or bottoming out, coolant in the exhaust, unburned fuel in the exhaust, etc. If you hear rattling that means your ceramic substrate "bricks" are broken into pieces. Most likely cause of that is physical damage.
 
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I Have been running at 180 on medium cold days (with my AutoMeter Pro Comp Ultra-Lite Silver face Electrical Temp Gauge that i know is accurate) , on hot days at 200 tops, i have my stock fan hardwired on low speed and leave them on all the time when my car is on with a 180 T-stat, trust me you do that combo and you will notice a big difference, i speak from experience, not assumption, i had a 180 t-stat before alone, didnt do anything, then i put a stock 197 back in, and hardwired my low speed fan to work while my car is on, then i noticed a little bit of a difference, then i threw back in a 180 t-stat with my hardwired fan (low speed) that i leave on while my cars on, what a difference, you dont believe me try it, you might just suprise yourself and thank me.... (i use to run about 230 when getting on it no matter what weather it was, not anymore) (what makes are temp to hot is the combo a 197 t-stat and fands that turn on st 215 ? and 230 ? ) also another thing i didnt bottom out at all with my car, so you can take that right out..my valve seals are kinda shot, have 150k on them, need to be redone (new short block about 7k ago, never did them)...because i have some smoke come out of my exhaust sometimes, and when i get on it.. i have sometimes got on my car in first gear and let go of the gas quick (forgetting to push in the clutch) and the car reved down quick but it was a jerk, i have dont that a couple times by accident, i know that wasnt to good for my cats...besides that... i dunno...maybe my mods ?

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Excessive oil in the exhaust would be another good way to ruin the cats, but it doesn't cause the bricks to crack apart. That happens from physical damage or excessive fuel in the exhaust burning in the cats and melting the bricks, from something like a misfiring cylinder or overly rich mixture.

If you're seeing operating temps of 180 and you haven't tuned it to run at that temperature (like with an EEC tuner and dyno), then that's asking for trouble - like Mike said with the stock computer it's going to be running too rich. And you'll get increased cylinder wear and lower efficiency. Might be a good plan to go back to 195 before replacing those cats again.
 
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