H-5-L

Aloha gang.
Car was running fine.Installed LG lontubes with x-pipe,no cats on my 99 c5,already had o2 sims on the rear o2's for a few years now.(origanals gutted)
After the install,the car didn't idle to good,got lean codes for both banks.This was using the front o2's and rears eliminated still with sims in the rear harnesses..(no change from before headers).
I called LG,they said for the off road kit,i am suppost to put the rear o2's in the front bungs and use the adaptors in the kit to plug them into the front o2's wiring harness.The rear sensors operate at a higher wattage and are needed since the NEW front o2's are way down stream now.OK,no biggie,rear o2's now in front plugged into the origanal front harnesses.now the car runs even worse.And now on top of the lean codes,i get lack of switching o2's codes as well.I checked for any intake leaks,none.
Any thoughts?
Mahalo.

vector1

check plugs and wires for correct hookup, might have a miss; check other wires in engine bay to make sure you haven't inadvertantly knocked something loose; check air intake and exhaust for leaks, expecially exhaust; then maybe the o2 sensors-be my guess. after this just wag it. good luck.

H-5-L

Thanks for the reply.I was under the impression an exhaust leak would make it rich?My troubleshooting guide says intake leaks= lean...exhaust leaks "trick" the o2's to rich?Is this not true?I will have to follow your advise.I don't have any miss fire codes,pretty hard to cross the wires,not sure they would even reach another cylinder.If nothing else,i'll have to borrow my friends scanner.
Damn,it is such a simple install to.
Thanks again bro..
Hum,just thought of something i didn't check,i wonder if i knocked off the vacuum to the back of the intake manifold,that would suck.

SideStep

Welcome to the LG header nightmare... Too many to list on this forum and Corvette Forum have the same issue...

https://ls1tech.com/forums/showthrea...slow+switching
https://ls1tech.com/forums/showthrea...slow+switching

Assuming you do not have the front sensor wires backwards, the problem you have you will probably always have now. I have tried EVERY trick in the book:

New Bosch sensors (rear type)
New Denso sensors (rear type)
Extra timing (trying to keep them hot)
Extra lean (trying to keep them hot)
Wrapped the headers top to bottom...

No success with any of it... I will say they (O2 sensors) are switching faster after wrapping the headers but still to slow and I get P0153 and P0133 about once a day...

Good luck...

H-5-L

Humm,nice info.
I didn't even think of a heating problem because there heated o2 sensors.
I will ditch this system if it still does this after iv'e exhausted all options.
Mahalos(thanks) for your input.

Purrvert

You can try letting the O2's warm up for up to 45 secs before starting car, give 'em a head start.
Running Kooks with all four sensors with no problems.

SideStep

Buddy has same mods as I but he is using Kooks complete exhaust system w/cats... no issues at all. I have seen several of his HPTuner scans and the O2s are switching like crazy... Needless to say when I go 383 Kooks will be there...

soundengineer

iTrader: (16)

2 things to significantly help your problem...
one.... get the headers coated by some jet hot stage 2 coating(series 2000)
this will help keep the heat in
two.... get some bosch #13111's

this combo usually fixes this problem...
otherwise.....run open loop adn ditch teh narrowband o2's all together...
amny of us have been in open looop for a long time with no problems and our fueling stays more consistent than wen we were in clised loop

H-5-L

Hey thanks guy's,i will get the bosch #13111's and try everything else also.

You guy's have been a big help.

H-5-L

One other thing i'm wondering,i don't hear much about bad idling.Mine almost dies at every stop,then it will catch itself,barely.Is this also common with the codes?
My car is a 99 c5,right now i'm running the rear o2's in the front.Is this the #13111 sensor i keep reading about?It seemed to run better with the stock fronts in there,the harness sure is tight though with the stock fronts in place to the stock harness.
To verify hook up,my directions tell me the driver side o2 goes to driver side harness and same for passenger side.
Thanks again for your help.

H-5-L

Update.........
Well,power is back,no more codes,i still need to scan and tune some,but my problem is solved.I bought new o2's..A/C Delco AFS-97's....square plug connectors.I already had adaptors to connect them to my front flat connectors.Just thought i'd add this..

minytrker

iTrader: (13)

LG's are great headers. I installed them on my z06 a month or so ago and have zero issues. They make alot of power and sound really good. Glad you found out what your problem was.

Purrvert

Monitor your idle air flow, short/long and adjust. Got mine dialed in with one warm up cycle.

H-5-L

Thanks for the tip bro..

Thanks to everyone for the advise.Without your alls help,it would have taken more time and money before i figured this out.