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Firstly new here so hello folks ! As for the quick background , i had a 2012 SRT for about 5 months and realized it wasnt what i wanted , ended up trading it in and usin that for a downpayment on a 2019 RT which i have been loving. So far I've added the borla atak exhaust system due to wanting more sound ( who doesnt lol ). Currently have some LT headers being shipped.
So for my question , How long can i run at basically stock if i get the headers installed before a tune is required ? Only shop in my area that i've been able to find wants 1k to tune it , and to hold my car for a week. I assume thats due to needing to get the computer unlocked or w/e and to dyno it. So any thoughts or insight would be greatly appreciated - rather not spend the cash to get the headers installed if i cant hold off on the tune for a little.

Thanks folks!
 

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2015 RT 5.7 M6
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Before installing headers, have extra O2 bungs installed so you can run a wideband. Running without a tune should be fine as PCM controls PT fueling and will correct fuel but when you get on it or go into WOT you may lean out a little. Just run premium fuel and don't go crazy with the pedal and you should be fine.
 

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Welcome to Challengertalk ;) You added a post "SXT* " I assume this means you had a 2012 SXT for about 5 months ?

A Guy
 

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Ive got bola s-type and longtube headers on a r/t 5.7 engine. I have no tune yet. Waiting for cam installation before the tune. I run it hard and have no issues. No leaning out. The tune will get you the most out of it but it will run fine without the tune.
 

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Are you logging with a wideband installed? Without a tune COT temp value is stock and may start adding fuel thinking the cats are running too hot. Most tunes raise the temp to avoid this.
 

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Are you logging with a wideband installed? Without a tune COT temp value is stock and may start adding fuel thinking the cats are running too hot. Most tunes raise the temp to avoid this.
Nope havent added the wide band yet. Waiting on the nitrous guage so i can wire everything at once. Hate going into headliner too many times for wiring. Much easier to do all at one time. Ive watched the 02's with the scanner to see if lean or rich at wot and all looks normal. Pulled a plug at random also and look fine. Dont have cats. Catless mids. No check engine light either. Figured id get a cat inefficiency code but nothing.
 

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So how can you say it is not running lean at WOT? At WOT the narrow bands are ignored and the fuel is purely interpreted from the WOT PE table. As for codes just wait until you hit the highway and meet the drive conditions for the fuel/cat monitors to start.
 

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Ive hit the highways and know how to read the 02's. I understand that at wot they are not that important but still tell me how the engine is running. Just cause the ecu doesnt use them doesnt mean they still dont read the exhaust. Scanner data is valuable to me to tell how its doing. I know drive cycles too. Used them many times as a tech and previous state inspector
 

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You sure you have a stock tune? Running catless with headers (and sometimes even with high flows) will generate DTCs. Just do a search, lots of guys complaining of DTCs because of running catless. Out of curiosity what was the error between desired and actual AFR? Were you getting any ST Knock? Reason I am asking is I don't want some newbies getting it in their head that they can run catless without a tune and everything is ok...especially guys with 6.4s.
 

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You sure you have a stock tune? Running catless with headers (and sometimes even with high flows) will generate DTCs. Just do a search, lots of guys complaining of DTCs because of running catless. Out of curiosity what was the error between desired and actual AFR? Were you getting any ST Knock? Reason I am asking is I don't want some newbies getting it in their head that they can run catless without a tune and everything is ok...especially guys with 6.4s.
Catless with no tune will 100% throw a code, otherwise people would never have to worry about passing emissions. After 5 seconds from when I start my car on a tune without the CEL turned off it throws a code. Did you buy this car used?
 
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You sure you have a stock tune? Running catless with headers (and sometimes even with high flows) will generate DTCs. Just do a search, lots of guys complaining of DTCs because of running catless. Out of curiosity what was the error between desired and actual AFR? Were you getting any ST Knock? Reason I am asking is I don't want some newbies getting it in their head that they can run catless without a tune and everything is ok...especially guys with 6.4s.
Yes i know theres lots of issues with cats getting inefficiency codes. I see those codes daily on cars. Sometimes its converter and other times its a separate issue. Scanner i have is for diagnostic purposes and wont tell me the the desired and actual afr. I know what the upstream 02's should read from years of diagnostics.
No the tune is definitely stock. Intake and huge tb on it also. Only reason im going to install the afr is for the nitrous. Then the 02's are not that important to me and the afr meter will become important. These computers will read and adjust fuel pretty good on there own. I also reset the trims and let the ecu relearn with the modifications ive made.
To get the most out of the aftermarket parts, yes a tune is very important. But you can install headers and still run a car, the factory ecu can learn on its own SOME. Now change injectors,cam,add boost,cubic inches and it should be cracked and ready for a tune after the parts are installed.
As far as the newbies are concerned, i hope they do their own homework from multiple sources and not just a forum before they even think about touching their car. I grew up in the auto industry. Was learning from my father and uncles and have been in a shop environment from the time i could walk.
 

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These cars a take a while to throw codes, i get one with my high flow cats cruising hwy once every 6 months. Not right when everythings installed
 

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Catless with no tune will 100% throw a code, otherwise people would never have to worry about passing emissions. After 5 seconds from when I start my car on a tune without the CEL turned off it throws a code. Did you buy this car used?
I built this car. I never buy cars that are ready to go. Its actually an 11sxt chassis and 15 dash,engine,trans diff, 18 rear brembos, 14 front spindles modified for brembos. Its all documented here in the build section. And no i have no check engine light on. No cats. Long tubes. All in build section with pics
 

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But you can install headers and still run a car, the factory ecu can learn on its own SOME.
WOT fuel is not learned it is specified by PE enrichment. ECU ignores O2 at WOT so how can it learn fueling? Fuel trims are only learned at PT and usually target stoich which you don't want to run at WOT. If anything it can pull timing thru ST knock but if it happens consistently then it will become LT.
996498
 

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These cars a take a while to throw codes, i get one with my high flow cats cruising hwy once every 6 months. Not right when everythings installed
FWIW I used to get a slow to respond on my bank 1 sensor 2 with highflow cats only on long highway runs. Replaced the sensor (after swapping sensors around) and added the foulers with catalyst in them (for good measure) and have not had a code for over a year (actually I think it is over 2 years now). Problem is the codes are permanent and cannot be cleared by scanners (even witech ones) and can only be cleared by the PCM. Disabling the rear O2s is the easy way but if you live in an emissions state like me you will never pass as monitors don't complete.
 

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I built this car. I never buy cars that are ready to go. Its actually an 11sxt chassis and 15 dash,engine,trans diff, 18 rear brembos, 14 front spindles modified for brembos. Its all documented here in the build section. And no i have no check engine light on. No cats. Long tubes. All in build section with pics
That's right I remember seeing the build thread. Anyways, maybe the downstream o2s are failing in your favor or something because on both my car and my brothers ram they throw codes from Catless very fast. What headers are you running?
 

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I am not trying to argue but what you are saying goes against every post I read about guys running catless headers. I run high flows and still had a code pop up which took some time to figure out why. Again I don't want newbies to read this and say "hey catless headers, no codes, no tune...I'll do that" and then they come on the forum saying please help I can't pass emissions or I am getting a SES.
 

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I can understand your point @ChallyTatum. I havent seen the code yet. Not saying it wont eventually pop up. Surprised me it hasnt/didnt. The op asked about LT's and the tune. That wouldnt be an issue. Then we started talking about my car. Ive got lots of work done, do it all myself.
Now would i suggest the newbies run out and pull their cats off and expect no codes? No. Will it pass an emissions visual inspection? No.
@JD40, my rear 02's are not failing. They are fine. Ive monitored them also. Nothing wrong, i just havent hit the drive cycle exactly perfect probably. Ill check it with the scanner tomorrow and see if the 02's and cats show ready or not and take a pic.
 
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