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Reply With QuoteBoth are bad for your car. If you're running rich, you'll waste gas and eventually burn out your catalytic convertor. If you're running lean you'll experience detonation which can damge pistons, camshafts and other engine internals.
Chip
Which one is bad for your cat lean or rich and why.....
Both are bad for your car. If you're running rich, you'll waste gas and eventually burn out your catalytic convertor. If you're running lean you'll experience detonation which can damge pistons, camshafts and other engine internals.
Chip
Chip
2000 Basalt Black Metallic GTZ
(Paint Code: Porsche LC9Z)
Genuine experience carries a lot more credibility than the ability to answer a question.
here's the thing my car at WOT usually stays rich.....my cat has recently been burnt out......but i only have my FPR set at around 38 PSI.....should I lower it down....
its normal for a car to run slightly rich at WOT... about 12 to 1.
and it should run slightly lean at cruise.. about 15 to 1.
neither of these should damage the converter, but the rich running is more likely to if done for extended periods of time. (im talking like an hour, here, but even then probably wont).
you must have yours REALLY rich.
How do u know ur running rich at WOT? DO u have a air/fuel meter or a AFC? Depeding on ur mods if ur motor is not really built up, i would turn down the FPR to about 32-35psi.. Since ur cat is burnt out, that means u can by a HFC to replace it..Originally Posted by b-boy_sky
I Shook You At The Track, My Boyz Threw Asprin On The Floor, They Said Now You Gotta Headache...
The illiterate of the twenty-first century will not be those who can not read or write, but those who can not learn, un-learn and re-learn.
It may be the header you put on it. I know that my moffler got it when I installed mine. I got the HFC with the Header. I don't run WOT very often though. Not til I get my rich/lean situation solved.
C.J. Cameron
RETIRED TUNER!!!!
"Keeping it Simple"
Please help me w/my ignorance. Wut's WOT? and wut does it mean if ur running rich or lean? Also can one only find this out if one has an FPR? Thanks
"....BIG got hit in the passenger seat, 'Pac got hit in the passenger seat, now i'm ridin' 'round in the passenger seat..." 50 Cent
WOT = Wide Open Throttle
Rich = more fuel in the air/fuel mixture than the stoichiometric ratio.
lean = less fuel in the air/fuel mixture than the stoichiometric ratio.
the correct stoichiometric ratio for a gasoline burning car is 14.7 parts atmosphere to 1 part fuel.
and nearly every car on the road (and all current mitsus) have a FPR.. which is a Fuel Pressure Regulator. its job is to keep the fuel pressure at a preset level. Most cars have a variable FPR.
yeah I have an air/fuel gauge......I lowered my FPR down to about 30 psi.....I think I just had it set to high.......everything seems to be doing better.......now I just need a new cat....
<div class='quotetop'>QUOTE(b-boy_sky)</div><div class='quotemain'>yeah I have an air/fuel gauge......I lowered my FPR down to about 30 psi.....I think I just had it set to high.......everything seems to be doing better.......now I just need a new cat....</div>
iight good to hear ur car is running better..
I Shook You At The Track, My Boyz Threw Asprin On The Floor, They Said Now You Gotta Headache...
The illiterate of the twenty-first century will not be those who can not read or write, but those who can not learn, un-learn and re-learn.
my car is running all over the place with respect to lean and rich. the guys who tuned my car didnt know shit about the afr so my car is relatively still untuned. Ross is putting the BB on my car next to fix this issue. but think of it this way, when you run really lean your car runs hotter. the hotter your run the higher your EGT and the more likely you are to burn a cat. the richer you run the more black smoke your car generates and the more likely you are to fowl O2 sensors.
well, in case you werent aware (as most people arent), our cars do NOT stay at one level. Even at a constant speed and throttle posistion, the mixture bounces back and forth about 10 times a second (plus or minus a few). Its looking for an average, not a constant.
and under acceleration, it will go rich.. under deceleration, it will actually shut off the injectors totally, going lean.
also, a rich mixture is actually more likely to kill a catalytic converter than a lean one, depending on the situation.
I've only heard of ppl ruining their cat from constantly running too rich but never from running lean.
[size=10]<span style='color:white'>. . . .</span>
Thats the only way i can think of to burn ur cat out...
I Shook You At The Track, My Boyz Threw Asprin On The Floor, They Said Now You Gotta Headache...
The illiterate of the twenty-first century will not be those who can not read or write, but those who can not learn, un-learn and re-learn.
an excessive lean mixture WILL kill a cat due to excessively high hydrocarbon levels.
hmmm...... wouldn't chance to kill your engine be greater than killing the cat if your running very lean?
[size=10]<span style='color:white'>. . . .</span>
probably not. the engine is tougher than the cat.
so when you decelerate your injectors actually turn off......I always wondered why my air/fuel gauge would go lean and then just not give me a signal until my idel went back down or I stepped on the gas again...... :idea:
yeah i noticed the same thing on my air/fuel gauge, but i found that out when i got it dynoed that the injectors turn off..
I Shook You At The Track, My Boyz Threw Asprin On The Floor, They Said Now You Gotta Headache...
The illiterate of the twenty-first century will not be those who can not read or write, but those who can not learn, un-learn and re-learn.
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