ok everyone i just finished my 6.0 swap...just to give everyone an update on what i did to my truck... I have an 02 yukon with a 5.3 and i took a 6.0 lq9 and swapped out my tired 5.3 for the lq9

i used only the lq9 block and 317 heads and used everything else off my 5.3

i test drove my truck and it feels sluggish and kinda bogs out on takeoff and when i slam on the gas...when i do this my service engine light is on and starts flashing???
what does this mean??

also i ran the scanner to check the codes on the check engine light and i get a p0171 and p0174 the def is to lean and also p0300 a randon misfire??

not to happy with the end result...not sure what i did wrong or what i need to do to fix this?? please help out guys?

I also have the 5.3 eng comptuter in it...also have the 6.0 computer laying around...would this be an issue...tuning??? should i put the 6.0 computer in it or get it tuned.

 

id start with tune and crank relearn i think. sounds like its getting lean from having that turd 02 tune from a 5.3 on it lol. but thats my guess. let others chime in

also check all the wires and coil backs and grounds

 

thats what i think also...the tune from the 5.3 but not sure would like some other opinions...i think im gonna change plugs and wires...clean throttle body and change fuel filter...i really dont think it should bog the way it does...it also shakes at start up when cold

 

You MUST GET IT TUNED. You cannot properly troubleshoot one aspect of your problem until it has the correct tuning in the pcm. It is running lean as **** probably causing the misfires. It takes more fuel to run more cubes. If you put the 6.0 pcm in it then it won't shift because I'm assuming it came from an HD and has 4L80-E trans tuning.

 

Injectors and all other sensors are identical from your 5.3. The MIL flashing could also be false because the 6.0 uses a misfire detection that is less sensitive than the 5.3. So 6.0 on 5.3 tune the PCM sees the information from the crank reluctor and is going WTF holy **** houston we have a problem and signaling the mil to flash but it could all be false.

 

Go take your stock pcm and have them put a 6.0 tune over your 5.3 tune. Then once the truck is running take it to them strap it to a dyno and let them tweak it to get it perfect.

I don't have a clue what your pcm from 6.0 is out of but you can't just swap them around. All kinds of factors service numbers between pcm's and years and software installed all make a difference

 

makes sense tamu...i know i need a tune...but also just wanna rule out anything i might of done wrong before i do...

 

10-4 especially where spending more money is concerned. Bug in a project are one of the most heart breaking problems there are sometimes especially at the end because no matter what cash is always short.

 

so true i will repost any changes tomorow and look into a tune on monday

 

Quit messing with petty stuff and get the truck tuned.