Bogging/hesitation under WOT

[TurboGP]

Hey guys. I finally picked up the new TGP, and everything's been great aside from one problem: When you're under heavy boost at WOT, sometimes it'll start pulling hard then hestitate/buck a couple of times and keep pulling again. When this happens, it almost sounds like a backfire/misfire and you can hear the boost rushing back out of the turbo as if you were railing on it and let off the gas. Frankly, that's exactly what it feels like. It doesn't do it all the time, and most commonly it happens around 75-80 on the freeway and right after a 2-1 downshift. Jeff M chip and x-over.

The stock upper charge pipe to intake manifold coupler looked pretty ratty and had some big cracks on it, so I put an aftermarket one on hoping it'd cure some of the problem. It could just be a coincidence, but it seems to be doing it a little less, but it still happens. R42LTS plugs according to Luke. Not sure of the age of them. I'll probably get around to changing them just because. Heated AC Delco O² sensor. I went over the vacuum lines and everything looks okay, couldn't see any cracks/breaks.

Matt and I were talking about it last night and that it could possibly be the wastegate. Preferably, I'd like to change that as a last resort because, quite frankly, it looks like a major bitch to change :laugh:

Any other insight? (and ugh, i'm so close to turning TGP #1 into a parts car)

[meltboy11]

is it possible that it's a MAP sensor, that is a similar problem I had with mine, except mine would actually stall in that situation, replaced the MAP sensor and haven't had a problem like that since.

[dogginred90]

I had that problem on a few ocassions. First one was plugs were gapped wrong. Second time I had a weak coil. It would spark but at WOT it wasnt strong enough and the spark was getting blown out. Hope it is something simply.
                                                    Shawn

[mfewtrail]

is it possible that it's a MAP sensor, that is a similar problem I had with mine, except mine would actually stall in that situation, replaced the MAP sensor and haven't had a problem like that since.

Did your car set a code when it dumped boost like that(like it would in an overboost situation)?

If it's not ignition related, it's probably related to the wastegate actuator or control solenoid. Did you try putting the stock airbox back on to see if the problem goes away Shaun?