2006 Nissan Sentra Please help

For the last couple of years this car has been displaying an intermittent problem that involves the gas pedal, TPS (or throttle chamber), or ECU/wiring harness.

Basically, when you drive the vehicle over slight bumps it feels like the gas pedal stops working and then comes on again. It's hard to explain, but picture yourself driving about 50mph and very quickly taking your foot off the gas pedal and then putting it back on. That's exactly what the car does. Sometimes, on the highway, it will start happening so much that the check engine light comes on with the p2135 code, and the gas pedal will completely stop working, making the car start to slow down. I can put the transmission into neutral, restart the car, and regain the use of the gas pedal. At that point I can put the car into drive and continue driving. I know that it's not related to the transmission, because I can go over those bumpy areas with the car in neutral and if I hold the rpms around 3k, I can see them jumping around like they do when the car is in drive. Obviously, it's much more obvious though when the engine is under a load.

I'm pretty confident now that the problem is related to the throttle chamber or the wiring harness. I would much rather it be the throttle chamber, since that would only take an hour or so to fix and do the idle relearn, however, I feel that if that's the problem, I should be able to have my wife sit in the car and hold the rpms about 3k in neutral, and my feeling is that if I rap on the throttle body with a light hammer tap, I should be able to replicate the issue. The problem I'm faced with, is that it doesn't do it when I tap the throttle body. That leads me to believe that it is a wiring problem. Also, it does it more when there is a weird weather change. Like going from extremely hot to a downpour.

Anyway, I know this is a difficult diagnoses, but if anyone can help I would really appreciate it. I have had the car since it was brand new, and even though I'm virtually broke, I can swallow a $500 part, but I definitely can't afford to get one done (or do it myself) just to find out that it's the other one that needs to be replaced.

Please help me. Thanks in advance.