Have access to EFI live, Any quick way to get a car close enough to drive without throwing codes.. Just put on full exhaust and dont want to throw codes.

Mods
ls6 intake manifold,
Vararam cold air intake
msd plug wires

Car runs fine untill about 5k rpms than throws lean codes

Today i installed a full exhaut
Billyboat long tubes high flo cats and axle back

I Have not started car up with new exhaut but i dont want to throw any codes for being lean..

Is there a way i can add fuel to safely cover myself so i can drive it around untill next week when i do the cam swap? Just want to get the car running close to where it needs to be so i can drive around and not have any problems..

And reccomendations on tuning are welcome as i am new to computer tuning and data logging.. Thanks, Ray

 

Wow so many changes all at once is a tuning nitemare !! To get rid of all the codes you'll need to set all the DTC enablers to "not reported"
Hi flow cats most always throw codes as do LT's
I wouldn't worry about any of those quite yet as they won't hurt the engine--best is to get it running for awhile then read all the codes 1st then delete them from the DTC list
A varrarram almost always throws lean codes-- A rich or lean code is thrown when the fuel trims go - or + over 25%--If you are getting a lean code its way off over 25% in closed loop---
To be safe you can add like 15% of fuel with the MAF table--temporarily say up to 7000 HZ--that will stop the lean code--
I would 1st check to see if your 02's are working-----LT's are notorious for them to fail----With you data logger and the engine idling and maybe revving it up to around 1500 some see it your 02 voltages are oscillating rapidly ( bouncing around quickly from .100 to .900 millivolts) If they are lazy--- you have an o2 heater issue--that requires another fix i can help you with later---IF they are flatlined at like .450--they are not working at all and most likely fouled

I'm not a fan of the MSD wires---The boots on the coils are too thick and don't snap on when installed---eventually they pop off and lose contact--make sure they "snap when you install them---A trick is to relieve the air inside the boot when installing them--i slide a very small zip tie into the boot along the edge when putting them on--this allows the trapped air inside the boot to escape --then when you hear them snap on---slide out the zip tie---
I wouln't run it hard or WOT till you get the P/T fueling sorted out and the ECM has learned out a bit---

 

Just turned it on and seems like it is searching for idle almost like a lopey cam... But took it for a ride and it ran like ****.. No power at all something deff isnt right, unless everything is correct and it is in dyer need of a tune... Almost felt like a huge exhaust leak.. Like i said before i went for a ride and it did not throw any codes but i didnt rev it past like 2k..

Strage it would run like **** and still not throw any codes.?? Is there a posability that there is nothing wrong and just needs a tune?

My buddy is going to come down tomarrow and throw 15 % increase in fuel trim as a start.. Just Doesnt have ANY power

 

I a going to add that when i started project i unplugged the battery, so after thinking i guess the computer is just relearning the idle with the new headers that is why it is hunting but it still runs like crap.. Feels like a carbeurated engine that has super lean mixture and super hesitates..

 

To get rid of the hunting and surging at idle---- 1st let it run and drive it for awhile to let the trims learn out at least a little otherwise if you make changes too early you'll always be chasing your tail as you're making changing with just temporary data as the ECM learns out
I've had best results with surging by :
addding 2-3* of timing in the " base spark tables" both in gear and in P/N
adding 10- 15% at a time to the " desired airflow table" both in gear and P/N keep going til it goes away or in gear you get a " cruise control affect" or in P/N a hanging idle---

 

yea just rechecked and the car again, and i switched the 2 post cat sensors.. so driver side goes to driver side and passanger side to passanger side... that is correct.. I rechecked the sparkplug wires and boots all are on the plugs and the coil packs.. It isnt hunting anymore for idle in park or neutral but the car is shaking quite a bit... when put into a drive gear either forward or reverse it drops to about 500 rpm's, and seems like it is going to die

 

The pass post cat O2 sensor goes to the driver's side connector, and the driver's post cat O2 sensor goes to the pass side connector.

This won't cause a rough running engine. The issue is with LT headers when the pass pre cat sensor is incorrectly plugged into the driver's side connector & vise versa for the other O2 sensor.

Russ Kemp

 

Ok---If it stalls or trys to die only when put in gear when stared from a DEAD COLD start--you need to make an adjustment to your "commanded fuel in open loop normal" table---With LT's this table has to be leaned out to trick the ECM into running leaner--I have mine set to around 16.0 in the start-up fueling area table of that table---At cold start up the ECM is in "open loop" before it warms up--and changes to "closed loop when the coolant temps reaches about 140* after already warm-- it is switched ftom open to closed loop via a timer--usually around 20 seconds--
IF it trys to dye on a warm start--after it has switched to closed loop-- when putting it in gear-- try to add another 10% to the 'desired airflow table"--in gear---
If that doesn't work---some larger cam require you to disable the DFCO---- Also try ading another 2* to the "base spark " timing table in gear--- Mine is around 26* in the low fueling part of the table--

 

So yea i played around like stated before and added one degree to initial base spark at idle and that smoothed it out quite a bit, we raised the idle to 900 and we disabled AIR.. Car idles now and doesnt stall at all.. Still dickin around with the exhaust to get it to fit exactly how i want it.. But once i get that i will go for another ride and hopefully be able to drive it..I actually went with a friend today to get his roush tuned and the owner made me a good baseline which i stated above what he did and it started and ran pretty decient...

Guess my other question would be why would bank 1 LTFT be 13 percent adding and bank 2 wanted to pull 1.6 percent? I called the guy that owns the shop and he recomended to let exhaust get up to full temp before trying to screw around with the long term fuel trims.. So i let car get up to 200 degrees reving it on and off for a good 3 minutes and bank 2 went down to 0 and bank one went down to 11 percent? any reason these two banks would be so far off with LTFT..

Thanks, Ray

 

Large variations from bank to bank in LTFT's are usually due to exhaust leaks-----
The 02's are being used to control the fuel in closed loop to the stoich AFR of 14.68-1 They use the fuels trims to make these corrections-- It could also be a lazy 02 sensor----To see if its a lazy 02 sensor--swap the 02's from left to right and see if the high trim follows the 02---If it follows the 02--its most likely the sensor---If the high trim stays on the same side---you have an exhaust leak---

 

Thanks everyone for your help problems is solved and its running awesome, Sounding even better.. Appreciate the help Thanks

The LTFT was high on one side because 2 wires a bank were barley on and after a removed the msd and put on the stock wires everything was fixed..