Bay Area Y2K_Z28

about a week ago i bough a set of used pace LT's & found a guy who would install them for a couple hundread bucks, it was a big mistake letting him do the work he did the S*****st! install ever! but long story.. so i get my car(2000 Z28 M6) back the next day & leaving his shop i got on it WOT to notice the diffrence & it ran like crap!.. & when im at WOT there's a lot of backfiring? my set up is Pacessetter LT's No cats, O/R y pipe, SLP LM1... Please help i need to figure out how to get it running solid again... in general the car just runs poor now(i can't even spin 2nd gear anymore).. the guy did throw in some o2 extenssion for the front o2 sensors but he left 2 other wires disconnected?... is it bad to continue driving my car like this? Please help me any piece of info will be appreciated thanks.

SS4Luck

iTrader: (10)

I bet the 2 disconnected are the rear 02 sensors.

Sounds like he broke a few spark plugs putting them in. Its really easy to do if they arent removed when you put headers on. Get yourself some NGK TR55s, a 6 pack and get to work. Its usually around 16-20$ for 8 plugs and takes anywhere from 45 minutes to 2 hours to do. youll notice a niceeeee difference

BLK02WS6

iTrader: (2)

Yep, my money would be on broke/cracked plugs too...

c5formula

iTrader: (55)

yeah check your plugs is super easy to break them damn things on a header install, i would go get a tune as soon as possible, since your two back o2's are no longer there,

greasemonkeysoldier

iTrader: (1)

i had this same problem after doing my header install...i left my spark plugs in when i did it so i replaced them afterwards...the problem was still there and i couldn't for the life of me figure it out...so i decided to check the sprak plugs again...and sure enough...2 of them were cracked....so i'm betting it's your spark plugs.....replace them...and if the problem is still there recheck your plugs for cracks that might have happened while putting them in....should fix your problem...

moehorsepower

iTrader: (3)

The rear O2's do nothing but tell you if the cats are working, It's the front O2's that control the fueling..

ThunderstuckN20

sounds like your running rich for 1, cracked plugs maybe? did you have any check engine lights before/after install? a tune would definitely help you, but is it completely necessary? No. check the plugs/wires/make sure no wiring was damaged.

Bay Area Y2K_Z28

thanks for the info.. but i did give the guy new NGK TR55's to trow in, unless his retarded A** did break/crack 'em when he put in... & i had no check engine light on before the install & ofcourse it did come on after since i have no cats

Bay Area Y2K_Z28

So the tune isnt really that necessary? cause i really did think that was the major issue?

wad02z28

It doesn't sound like a tuning issue but I would still make plans to try and get one. All I can say is check all spark plug wires and plugs again. It is very easy to pull wire out of boot. Also pacesetters do not come with 02 extensions you either have to make your own by extending factory plugin or buying after market. Might not be a bad idea to check 02 status with scan tool. Oh yeah and also what did your mechanic gap these plugs?? Just some ideas

Bay Area Y2K_Z28

i really have no idea what he gapped them to? whats the gap supose to be on them?

LSxPwrDZ

iTrader: (4)

I had a 2004 GTO come in the other day that had just done a Kook's header install and was doing something very similar. I had to find it the hard way by starting the tuning process and my afr's were all over the place and it had an intermittent dead miss that was really prevelent at WOT. So I decided to check the plugs to see what they looked like and while I was pulling the plugs found that the wires werent even clipped on the driver side plugs lol. So I put a new set of plugs in anyway and then re-installed the wires correctly and it ran like a champ!

greasemonkeysoldier

iTrader: (1)

what's funny about this is when i had the same problem i made a thread similar to this one....
https://ls1tech.com/forums/pcm-diagn...8408-tune.html

but as i said...turned out 2 of my spark plugs were cracked...and the MSD wires i had put on were kind of crappy...the boots seemed a tad too long for the plugs....the boot around my #5 plug was all black around the tip of the boot so i don't think it was sitting on the plug very well....and i had like quadruple checked my wires to make sure they were on good too....so yeah...buy a set of cheap/stock plugs and put them in (carefully, lol) and see if that fixes the problem...if not try new plug wires....or even do both at once and save yourself an extra trip if its needed.