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Hey everyone, could anyone out there help with the number ranges I should be looking for on my car? I just had a cat go bad after only 2 years and am trying to find out why. I don't really know what to look for on the STFT or LTFT or the O2 sensors or the MAF numbers. Not sure what the number ranges should be around on these. Any help would be greatly appreciated.
What are you using to tune with and was COT turned off? I'm not sure exactly what you're asking. Are you looking for the data in the tables or where you want the car to run? You want LTFT's at zero or slightly less. O2's are a terrible way to judge your AFR but will ballpark your AFR if you're on stock manifolds. At WOT the O2's should be in the 880-890 range but like I said that's a terrible way to guesstimate your AFR. A wideband is much more accurate.
I am just trying to get the general number ranges for these when watching them with LS1Edit. Pretty much stock tune in it right now but I had a cat go bad after 2 yrs. and am trying to find out why, bad O2 sensor, MAF, or injector, or anything else the numbers will tell me. Any other ideas where to look? Thanks for the help...
The only thing I can think of right off hand to check would be the COT (cat over temp)setting. That adds extra fuel to cool the cats and if it's turned off it will kill your cats. Define "pretty much stock tune". Did you flash a tune to it or did someone else and do you know what they changed? Might just be a case of a bad cat too. Might not necessarily reflect a problem with the car. If you have a log you can email it to me and I'll take a look at it. I'm no tuning genius or anything but I'll be glad to look at it for you.
pretty much stock tune?? so is it or isnt it? do you have any mods? As Orion said, it could've just been a bad cat. Watch your trims make sure you're not too lean or rich.