I added LT headers and a 3" y-pipe yesterday. All 4 o2 sensors are installed and hooked up. No CEL. Seems a little more sluggish now like when it was stock.
When I tuned my truck before the headers I only disabled the mds then smoothed the fuel n timing tables. It was a huge upgrade over stock. Now with the long tubes on, I'm not sure where to start on my tune?
hopefully someone will reply with some info on this! ive searched and not much on LT and o2's.
By the prickle of my thumb something wicked this way comes!2008Chrysler 300c! 2013 heads/220/230 comp cam/LTheaders/FTI 2600 stall converter.
Did the headers move the o2 sensors by any noticeable amount? Ive seen that cause some issues before and you have to change the o2 sensor delay. Usually under Engine-fuel-02, it should be labeled o2 delay or integral delay something along those lines if I remember correctly.
When in doubt, Throttle out
Do you have before and after logs?
When in doubt, Throttle out
thanks for the reply. i have nothing on the calibrations before the mods. the o2s were moved about 10inches also used the downstream o2 harness to make up the difference. i will look into the delay table and try playing with the numbers.
By the prickle of my thumb something wicked this way comes!2008
You'll have to use o2 sensor harness extensions or make your own and plug the o2s back into the upstream harness. I would do that first then go after the delay tables.
Same here but i have taken out some ve at lower rpms and helps lt but isnt quite enough. would love to hear more about it too is hard to find any details for stoich metric.
open throttle angle slightly by changing position voltage in electronic throttle menu then add +1 to ve tables save and run fuel trim reset, after a few times you should get a good feel for your LT fuel trim levels. may have to adjust key areas for idle. More air out needs more air in. dont increase the top end ve tables to much just focus on your regular rpm range from idle. dont change anything about the o2 sensors delay, turn off any applicable or associated engine light untill u find a sweet spot. hope this helps
Last edited by tmanplanet; 04-10-2022 at 08:22 PM.
13 hemi 1 7/8" jba long tube headers 3" y pipe straight through to 2 1/2" stock resonators
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