Quote Originally Posted by Skinny Pedal View Post
Your tune needs work, maybe? All long tube manufacturers advertise those numbers.

Hey, buy my headers. You will also need an engine tune...... WOW 30hp after headers aaaannnnnnddddd a tune.

Its a tuning site, we know what happens when you move the O2s further down stream with long tubes. Well, what needs to happen anyway.
Honestly in open loop or PE not much at all happens from the o2 placement. My tune is just fine and my part-throttle air/fuel ratios are right where they should be. I have been tuning long enough I know how to fix the tune and adjust the transient delays for the 02 sensors as well as the proportional gains and durations.

I guess I should mention I got a 6.0L with a bent crank snout and a broken compressor mounting boss cheap today for those that think I am anti-LS. It is destine for a lightweight sports car where its potential can be realized.

I think it was funny that someone complained about my L31 using the 0411 PCM. Its alot better than the LT1 era PCM that my engine started with and it alone was responsible for a noticeable fuel economy and driveability gain over the black box. I am about to dip further into LS components and install the EFI Connection 24x kit on the old L31 and possibly drive by wire if I feel like digging that far into the harness.

You may also notice where GM did not have the US emissions laws to contend with they kept the TBI engines well into the OBD2 era and kept the old L31 well into the GMT800 trucks. You can buy 2004 GMT Silverados in Mexico that have the 5.7 L31 from the factory. Its definately not a bad engine and certainly cheaper for GM just couldn't pass our newer emissions standards.