peevlos

I've had the GMPP turbo upgrade for the past 1500 miles. 2 weeks ago I installed a Hahn Catless dp and 3" exhaust.

I was getting boost of around 22-24psi now it has dropped back down to 15-17psi. I spoke with CED they said that they doubt it is a flash problem. Don't know if it could be the extra hp of the Hahn setup giving me more engine movement or what?

No codes, like others on here.

I have an appointment to bring it in on Friday. I'm also wondering if the service department will give me crap over the dp?

any thoughts or input would be greatly appreciated...

I thank you all in advance,
-Brian

gcsd3742

I had the same issue after I had my custom intercooler piping and intercooler installed. I had it reflashed. worked like a charm afterwords. your going from restrictive piping/ and bigger now. it has to relearn....

peevlos

That's all I'm hoping it is.

Although, I thought the GMPP upgrade eliminated the whole re-learn thing

asanti

I'll keep my eye on this, after doing a few test runs after installing my IC and hotside piping, I see boost not going a high as normal., I CAN feel a big difference in torque from the butt dyno lol. I'll get it dynoed once everything is in.

peevlos

I believe our SS's share "parts" from the same donor...

gcsd3742

Just trust me. Been there done that already... Listen to whom's already been there done that........

asanti

That they do peevlos! Although I spoke too soon: I got a CEL this morning so now I have to find out what it's coming from, the IC or the piping.

Later
Allex

asanti

So even the GM upgrade needs to be reflashed after installing a bigger IC + piping??? I don't have any other "tune" other than the GM Turbo upgrade... please enlighten an SS noob.


Also Peevlos: how'd you get the K&N to fit w/ the stock airbox cover? I assume you trimmed that plastic box underneath?

Thanks!
Allex

gmdealerguy

Seems a lot of us had issues. Mine was installed in May 2009. Got 22-24 lbs of boost all the time......then same thing as you.......now I hit 20 tops at times. Have not seen over 20 since maybe August of 2009.

peevlos

I didn't think it needed to be... but apparently I'm wrong. making my wife right once again.

fit with no alteration. I have read that people have trouble fitting them. I will check the part # tomorrow