Ls wiring speed sensor

tommy450r · Mar 9, 2015

When yall are having a ls harness cut down an computer flashed what all do u guys have removed??

Knock sensor
Mass air
O2 sensor

It will be on a stock 5.3 for now an I will swap to a built 6.0 next winter. So what all do I keep an what all do get rid of? It will be on a bouncer 5.3 th350 205

What are yall doing for a speed sensor on the np205?

02Jimmy · Mar 10, 2015

Re: Ls wiring

I did away with the O2 sen, kept the mass air and knock. I can give you a guys number that forgot more last night in his sleep then most of us know about LS tuning. He could have saved me enough money to pay for his tune if I would have called before my build. i had several things wrong in about 1 hour he had my 5.3 screaming!!! They love more timing with good gas, 93 min. I'm not sure about posting his number without talking to him first so PM me and I can hook you up if your interested.

Mortalis5509 · Mar 10, 2015

Re:

I ran o2's.

zjtrey · Mar 10, 2015

Re: Ls wiring

you can delete the o2s and the maf but you can get more out of the motor if you leave the maf and at least the upstream 02's.. most guys delete the downstream ones for simplicity.. you can delete all the egr stuff too.. talk to whoever is gonna do your tuning before you cut on your harness..

pholmann · Mar 10, 2015

Re: Ls wiring

You would be better off to keep the front o2 sensors, the knock sensors and definintely keep the MAF. Without it, it reverts to speed density like the old TBI setups.

NTIDWELL · Mar 10, 2015

Re: Ls wiring

If you don't wanna **** with cutting down a shitty wore out harness call larrys electric in Illinois send him your computer he will do all deletes and build you all new harness with everything labeled and simple 3 wire hook up a lot cheaper and cleaner lookin than painless kit he has done all of mine

As far as deletes egr, back two O2 sensors,and all smog **** I kept everything else a lot of people prefer to broad band tune but my dyno/tuner prefers not to broad ban tune. Whatever you decide spend the extra money and get it dyno tuned All mail order tunes are just to be able to start and load to get to dyno. I ran my first motor on mail order tune for a yr before dyno tune and it was night and day difference

tallnate · Mar 10, 2015

Re: Ls wiring

I run MAF, MAP, TB, Crank, Cam, ECT, IAT, Knock sensors, front O2's and the APP for my DBW. Mine is gen IV so it needs to see signals from the cam and crank to control the VVT. Really all that needs to be deleted on any ls is rear O2's, and emissions stuff as far as I know. The VAT's and other junk just gets deleted on the computer tune.

tommy450r · Mar 10, 2015

Re: Ls wiring

OK thanks to everyone that's posted I'm gonna box my harness an computer up an get em shiped off I'm ready to get this thing running.

Will I need to have any wires extended to flip my intake around? I will have to flip it to keep the MAF

Also is there any special o2 sensor that y'all would recommend getting or just the factory 5.3 unit??

NTIDWELL · Mar 10, 2015

Re: Ls wiring

tommy450r said:
OK thanks to everyone that's posted I'm gonna box my harness an computer up an get em shiped off I'm ready to get this thing running.

Will I need to have any wires extended to flip my intake around? I will have to flip it to keep the MAF

Also is there any special o2 sensor that y'all would recommend getting or just the factory 5.3 unit??

Yes you will have to extend maf sensor wires or reroute them inside of harness

hokie_yj · Mar 10, 2015

Re: Ls wiring

tommy450r said:
OK thanks to everyone that's posted I'm gonna box my harness an computer up an get em shiped off I'm ready to get this thing running.

Will I need to have any wires extended to flip my intake around? I will have to flip it to keep the MAF

Also is there any special o2 sensor that y'all would recommend getting or just the factory 5.3 unit??

Definitely the MAF, possibly the MAP, and if your motor is DBW you'll also need to extend the wires for the TB.

I just bought a new harness for my build from Pacific Fabrication. It's a big chunk of money, but I highly reccomend them. I had a cut down factory harness that came with my motor, but it was just going to be a pain to make it work. They will build it exactly to your specs, and it's a really nice harness. They use a really nice waterproof fuse/relay box, and it's a simple 4 wire hookup. I've called them back a few times already with questions, and they've been great to deal with.

tommy450r · Mar 10, 2015

Re: Ls wiring

Ok cool I will have them moved.. I'm gonna run a cut down harness for now because I'm gonna switch to a built 6.0 next winter or sooner if this wore out 5.3 lays down on me before then...

On my O2 sensors I will just be running headers with the little inserts welded in them do yall think that will cause much of a problem on the sensors reading right??

mna0121 · Mar 10, 2015

Re: Ls wiring

All mail order tunes are just to be able to start and load to get to dyno. I ran my first motor on mail order tune for a yr before dyno tune and it was night and day difference

Truth right there, never heard it explained any better brother. RTR

hokie_yj · Mar 10, 2015

Re: Ls wiring

tommy450r said:
On my O2 sensors I will just be running headers with the little inserts welded in them do yall think that will cause much of a problem on the sensors reading right??

I hope it doesn't because that's what I've done on mine. I measured the distance that the O2 bung was from the exhaust ports on the stock manifolds and tried to get it pretty close to that same distance on the headers.

pholmann · Mar 10, 2015

Re: Ls wiring

Worst case it'll be a little rich. No biggie.

bushhog750 · Mar 10, 2015

Re: Ls wiring

I prefer speed density tuning on factory based LS injection. Removing MAF, and all 02's keeps it simple and from robbing power or running like **** when an 02 goes out or MAF shits the bed. Sam Daffron who tuned my motor said that's the only way to go in a buggy running factory injection. But everyone has different opinions.

02Jimmy · Mar 11, 2015

Re: Ls wiring

I tried running O2 sens in headers and it DID NOT WORK! Ran real fat wouldn't idle AT ALL. Tuner said needs about 4 ft of exhaust behind sensor??? Im saying talk to a tuner now before you spend money that's not needed. I have a couple new O2 sens for 5.3 I will sell CHEAP!

02Jimmy · Mar 11, 2015

Re: Ls wiring

I will agree with Larrys Electric in Ill being Awesome at setting up the Loom. Just plug and play...

tommy450r · Mar 11, 2015

Re: Ls wiring

i dont have the room too add any exhaust so if the o2 sensors will cause problems i need to figure something else out.

zjtrey · Mar 11, 2015

Re: Ls wiring

the upstream 02's are normally in the header or just below it.. you'll be happier with the motor if you keep those and the MAF like TBI toy said..