Since i have installed the GM stage 2 with 2.8 pulley i got these problems

1 - The engine misses at low & high RPM
2 - Often got CEL
3 - Some backfire
4 - Seems like the exhaust is choked to the throat (lack of flow)

I use NGK BKR7E gapped at .040
my mods are in my signature

Anyone ever had some of these problems ??
Where should i start looking for the problems ??

Any help or comment is greatly appreciate
i hate to have a 2006 car running worse than my old 350 4bbl 1985 Z28

Thanks
Rick

 

What was the CEL? If you can't read it, take it somewhere like Autozone or Discount Autoparts, they'll usually read it for free.

 

maybe a clogged cat?

 

your running the same exact set up as me (i got the injen intake tho) and i have not run into any of those problems... what code are you throwing?

 

sounds like the cat, my 2.8 stage 2 runs great.

 

def sounds like a clogged cat

 

gap ur plugs at around .37

 

i'll take it to someone who'll tell me and i'll tell you the CEL code

 

I have problem 1 and 3 with my set up. I'm running so rich the damn body kit is starting to turn a little dark around the exhaust. I'm thinking about putting my stock plugs back in and see if I can get a better burn.

 

Did you reset your PCM after installing the 2.8 pulley? If not, disconnect the negative battery cable for 3 minutes.

 

That sucks you screwed away your warranty by putting the 2.8 on. Otherwise you could take it in to GM. Its prolly your cat. Gut it and avoid future problems.

 

He didn't necessarily screw away anything. If GM voids his warranty, they have to prove the 2.8 was the cause of his problems, not just claim it. Magnuson-Moss act to the rescue.

 

Not really, all he has to do is swap the stock Stage 2 pulley back on and take it to the dealer. If the problem is still there w/ the S2 pulley, then they will fix and know no better. I would go that route if you can. Thats why I went w/ the PB 2.8. It takes a total of what 30 seconds to swap it back?

You can take the car to autozone and get the code read for free. Write down the code and list it here or search for it on google and it should tell you whats wrong. Ive had the 2.8 for the last few months and it runs great no problem.

Can someone explain problem 1 as I dont understand it?

 

It could be the MAF going bad from your K&N, take that out and clean it. It's probably your cat though, how much boost are you seeing?

 

Ahh, nothing like cheating GM. Guess I need to get a spare supercharger setup stock so I can just swap it in and out when my overboosting creates problems.

Sounds like you actually have a MAF sensor related problem

 

Yet again another hopeful believer in the famous Magnuson-Moss Act....

Let me refer you to my post in this thread
https://www.cobaltss.net/forums/show...t=26395&page=2

 

I got the same thing 2 weeks ago, here are my symptoms:

If in 1st gear in dips in to the redline, and it cuts off, it's starts to feel very sluggish when i come to stop and start again normally in 1st 1st gear. sounds like it is struggling to rev up and bogs from the 1st to 2nd gear shift.

When i was running against a mustang on the freeway, i topped out third (no fuel cut-off, perfect shift!) then up to 125mph in 4th. It conrinued to cruise fine on the freeway. When I got to the off ramp, again it starts with the sluggish bogging all over again.

The way I fix the problem is that I turn off the car for about 5 minutes and re start the car, then it works fine.

This never happened while I had my stock spark plus on with the 2.8 pulley (for about 3 months), only after the NGK BKR7E plugs were installed (about 1 month ago) and gapped at .040.

I'm going to put the stock ones back in, as it ran much better with the GM stage 2 and
the 2.8" pulley.

My mods are:

GM Stage 2 + 2.8" pulley
K&N Intake
GMPP exhaust
Ingalls TB (piece of crap bends, not stiff at all)

 

How is he cheating GM? You and I both know adding a 2.8 pulley should cause 0 problems.... If a problem does arise either something was done wrong, or there was already something wrong. (how can you do this wrong tho? it takes what 30 seconds?)

Its really GM cheating us for adding parts that we all know do not cause issues.

Exaust - Oh sorry your header went bad because of your cat back.

Intake - sorry your Tranny went, but you where giving your car too much power w/ that CAI.

I mean seriously, whos really cheating who?

Oh and as far as the spark plugs and .40 gap. Try like .35 and see if the problem goes away. You may be throwing too much air into your car and blowing the spark out before it can be ignited and hence and engine miss fire. THE CEL WILL TELL ALL! WHAT DO YOU THINK ITS THERE FOR

 

x2 and why bulid a tuner car if your gonna have a **** fit if people tune it ? But i have been thinkin about doing the 2.8 but after i do it i would want to get my car tuned to get the most out of it.

 

PM sent. It's definitely your CAT bro!

 

cat cat cat cat!

 

If that be the case, return your stock pulley into place. if problem is still there like I said above, its obvious the new pulley had nothing to do with it, so take it to the dealer

 

Thanks everyone !!! !!!
I'll get that CAT changed & i'll give updates

Rick

 

Dude, i've had some similiar problems. Here's what I did to fix them.

-Those BRK7E's just wearn't burning hot enough for me, I switched to the IX's.

-Your CEL is most like a Mass-Air High Voltage reading, re-set it and don't worry about it.

-Like everyone else said, check that cat, mines been replaced once, and i'm working my way towards a second as we speak.

 

OK I have almost the same proble with almost the same mods as him.
My mods are
K&N intake, GM stage 2, 1 step colder plugs, Catt back, and PB 2.8. I tried puting the stock plugs back in but I replaced them to try to fix the problem in the first place. I reset the gap on them to .37 and even tried .40 and nothing helped.

Im seeing about 17.5 PSI max right now.

Ok now my problem

At WOT in any gear some times the car will miss just for a sec and then go agen like nothing ever happend.
And every now and then I will start the car and it will stall right away. After that the car will restart but it will run like its only running on 2 cylinders????? WTF!!!
If I shut it off and let it sit for a few min with the Key off it will run fine. If I let it run it will run like that untill I shut the key off for a few min. Even if I stall it and restart it. If the key was not turned off it will run like crap!

And I have to clean the black crap off my bumper ever 3 days!!!!!!!! 3 Fing days!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!

The dealer ses theres nothing wrong with it and that the car runs fine for them?????

I give up.

Later