Ntense90crxsi

I have a plx wideband in my factory exhaust location and with my open dump exiting fuel and exhaust gas before the wideband, is that going to effect my readings, another words, it is useless to have a wideband with a open dump because it is not accurate that way anywayz? I also have a boost problem, last time at the track, I was running 16psi all night, no probs, I tried to turn it up to 18psi one pass. Well it went to 18psi in like 1st or 2nd, and then back to 4.5psi for the rest of the run two or three passes. I turned it back down and it will still only boost like 4.5psi and sometimes jump to 10psi occasionally. I noticed that if I turn it up while boosting it will jump up, but as soon as I shift and get back into it, goes right back. I thought it might be the turbo so I replaced it, now I still have the same problem as before. I unhooked the hoses on the wastegate to see if it would boost past 4.5psi, but it still is doing the same thing, I even just hooked up the top of the wastegate straight with no controller in attempts to hold it shut, but still the same thing. Only thing I haven't tried is to actually take the gate off and putting a blockoff plate on to see if it will boost any higher. I am using a tial 38mm gate, profec b, drag mani, t3/t67 turbo, etc. I have checked all my plumbing 100 times and even tested the intercooler. I am lost in this boost problem and need to fix it asap.

Ntense90crxsi

bump for help on wideband question, fixed my boost problem.