I installed my plog a few days ago. I don't know how this happened, but while bolting up the cross-over pipe to the plog, I could not get one of the cross-over bolts to screw in all the way. I removed the bolt and somehow managed to strip it and damage the inside thread of the plog, therefore could not get the bolt to even begin to screw in at that point. I went to Lowes and could not find the correct length bolt of the same size to replace the factory one I stripped, so I ordered a couple new ones from ZZP and am currently waiting for them to arrive. I still however have been driving my car daily with an exhaust leak at the cross-over which I can clearly hear (only have one bolt holding plog to cross over). The car drives perfectly fine, but I noticed when I give it WOT that it begins to hesisate and sputter upon hard acceleration. I will see the RPMS surge back and forth a bit while they climb. This all started after I installed the PLOG. Could it be because of the exhaust leak at the cross over, or is it because of my stock PCM not being tuned for the plog? I have an overkill PCM on order hopefully coming soon... Like I said the car runs perfectly fine otherwise... Just like it has been for the passed two years... Any ideas?

in short: Yes.

Reason: you're losing back-pressure by having that exhaust leak before the muffs. Also, you're not running the cat like you should. If the cat dont act right, it makes the O2 sensors not act right, which sends bad faults to the PCM, which makes the engine not perform right. You would see similar symptoms should the catalytic converter become faulty.

Either do the quick and cheap fix of sealing the front y-pipe, or go ahead and deal with it until you install the exh mods. Problem with waiting is that you will cause premature wear on the cat. Good luck, and happy hunting trying to kill those gremlins

I wouldn't go WOT at all if its doing that. Your o2 sensor is probably freaking out.