Question for tuning Gurus regarding O2's and open/closed loop
06-06-2018, 10:24 PM
#1
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Question for tuning Gurus regarding O2's and open/closed loop I'm having the common issue with the P0133 and P0153 codes being triggered by my LT headers. If I set the codes to option 3 in HPT, will the car still run in closed loop if the computer senses an issue with O2 slow response times?
06-07-2018, 12:26 AM
#2
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you should be adjusting the closed loop proportional data so the delayed response doesn't cause DTC to activate.
the car should stay in closed loop if you select no MIL light and untick the SES box. your scanner will confirm this
the car should stay in closed loop if you select no MIL light and untick the SES box. your scanner will confirm this
06-07-2018, 12:42 PM
#4
Hes correct along with trial and error of the switch point, which i personally bumped to .450 on my own car up from 3##. Bascially comes down to the car drowing the o2 sensor with fuel. They get "stuck" and no longer swing. I also tend to remove any idling timing increases most tuners will throw in. Stock timing to keep the exhaust hotter.
i cut the fuel on mine by roughly half along with increasing the time frame. Doesnt take much fuel to trigger a swing on a LT car probably due to the exhaust not nearly being as hot as it once was when you had manifolds.
i cut the fuel on mine by roughly half along with increasing the time frame. Doesnt take much fuel to trigger a swing on a LT car probably due to the exhaust not nearly being as hot as it once was when you had manifolds.
06-07-2018, 12:54 PM
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Hes correct along with trial and error of the switch point, which i personally bumped to .450 on my own car up from 3##. Bascially comes down to the car drowing the o2 sensor with fuel. They get "stuck" and no longer swing. I also tend to remove any idling timing increases most tuners will throw in. Stock timing to keep the exhaust hotter.
i cut the fuel on mine by roughly half along with increasing the time frame. Doesnt take much fuel to trigger a swing on a LT car probably due to the exhaust not nearly being as hot as it once was when you had manifolds.
i cut the fuel on mine by roughly half along with increasing the time frame. Doesnt take much fuel to trigger a swing on a LT car probably due to the exhaust not nearly being as hot as it once was when you had manifolds.
06-08-2018, 10:44 AM
#6
Run it in open loop at idle and closed loop once throttle is applied. This will get around a lot of issues, especially if you have a big cam.
The main issue with LTs is they move the O2s back. Set the switch point to 450 and set PE EQ Ratio upto 1200 RPM to 1 and TPS% to 0 in those columns. And set your EQ Ratio in Open Loop to 1 over 158 degrees. Then you can use your VE table or MAF transfer table to run leaner than stoich for a more stable idle.
Once throttle is applied, it shuts off OL and goes back CL based on the PE TPS% table.
The main issue with LTs is they move the O2s back. Set the switch point to 450 and set PE EQ Ratio upto 1200 RPM to 1 and TPS% to 0 in those columns. And set your EQ Ratio in Open Loop to 1 over 158 degrees. Then you can use your VE table or MAF transfer table to run leaner than stoich for a more stable idle.
Once throttle is applied, it shuts off OL and goes back CL based on the PE TPS% table.