Hello,
I was told to post this here because I may get better responses. Last year, my car had a yank 3200, asp pulley, lid, slp longtubes w/ offroad pipe, borla, lca's, and nittos. I ran consistent 12.7's at 108-109. Anyway, I decided to go with a stage 2 heads/cam package, as well as the ported holley intake, a ported throttle body, a 160 tstat, ngk's, and a pace mafs, as well as dyno tune. The car put down 401.3 rwhp (up about 85 rwhp from the last dyno I had at a different place), which I was impressed with for an auto. As I was driving the car after I picked it up, I noticed a few things. First, the car would blow a good bit of dark smoke anytime I gave it alot of throttle. Second, the gas mpg when driving in 3 went from 16 to 11 (which seems crazy). Third, the car would occassionally flash the ses light. Not normal things! Anyway, I finally got a great cool racing night, so I took it to the track. It consistently ran 12.5's at 109-110 (and on the first two runs the car was putting out a decent amount of darker smoke all the way down the 1/4 track). About a tenth better and 1 mph more than before the mods!!! I don;t get this because if there was a problem, wouldnt it have shown up on the dyno?? I'm very nervous about what this could be for many reasons: I paid ALOT of money for the work and parts, and I dont want to hurt my car by driving it if there is something wrong, not to mention I wanted some high 11's with the new power, not a tenth better!! I contacted the place that did the work (a very reputable, fantastic place) and theyre gonna look at it for me. What do you guys think this could be? It seems to run fine when driving around, so I dont get it. I want to make sure everything is ok before I leave this time (the drive is 2 1/2 hours away). Any help that can be given is appreciated

 

A couple of things come to mind because I had similar problems after heads were installed on my car:

1) The smoke is probably oil -- it will look blacker if you are running heavier oil (ie 15w40). Check your oil level. Mine still burns oil like a **** after the heads-- I am hoping to resolve soon. I think mine is a valve seal problem combined with an existing PCV valve problem -- check to see if their is oil in your intake area and since you didnt have this problem before definately take it up with the shop.
2) I also had a ported ls6 intake (not a holley, but same idea) and the car ended up losing power with that, especially down low because of the runner velocity. I have a dyno graph on my website, if you are interested in seeing you can find it from the link below. The holley may be further costing you because it is metal and absorbs more heat, thus it may actually be costing you power despite looking good.
3) borrow an ATAP or get your SES light read, dont guess, find out what the problem is.
4) why are you driving around in 3?
5) did you witness the dyno? If not id consider redynoing it somewhere else.
6) your times could be slower than anticipated too because it is hot and humid in most places

hope that helps a bit.

 

The flashing SES light is normal for a cam upgrade; this means the PCM is detecting low rpm missfires. You just need to have the missfire test deleted or desensitized with LS1edit. The lack of power might be due to needing a better PCM tune after the heads and cam, or did you even have one done?

 

A good tune job will generally take care off all your symptoms. My car still flashes the SES light every once in a while, but i goes off after a few minutes. What size NGks are you running and at what gap?

 

My SES light did the same after the heads/cam install-its just the PCM detecting it and doing its job you can have the misfire deleted so it wont cause the SES light to do this.Also for track times that just doesnt seem right-I would have this further looked into maybe better tuning is needed also maybe LS1 Edit that does wonders!!Let us know how this turns out and what the deal is!!

 

I have heard that this may be a bad 02 sensor. I'm not sure about this, so let me ask you guys a few questions. First, could that be an explanation for these problems? Second, since I have an offroad pipe, would that change any 02 sensor type scenarios? Third, when I a-tapped my car, the L-Term for bank 2 had nothing but zeros; is this bad, and if so, could this be an o2 sensor problem? Any help you guys can give me will help me IMMENSELY! Another thing, I spoke to the shop, and they said alot of cars will put out some black smoke under alot of throttle, and when they dyno it, its not rich at all (sometimes even lean). Can the smoke be a normal thing with a setup like this? Thanks guys!

 

Sounds like you could have an O2 that is starting to fail...I would also agree that if you change out ur 02 you will still probably have the flashing SES untill you get rid of the mis-fire detection