This past weekend I had a N20 back fire through the intake and the car is ok and runs fine if I unplug the MAF so I naturally thought the Maf was blown out, I got a new one and same problem,

So I started listening under the hood and noticed that the TB plate for my N20 seemed to have a leak between the TB and the intake, so my question is ....would a leaky TB gasket cause the car to run and Idle like Cr*p???

Thanks!

 

Sure.... that's a vacuum leak. It means the MAF isn't measuring the correct air flow, forcing the PCM to compensate using the long term fuel corrections. It makes sense that unplugging the MAF would help, since the PCM defaults to speed-density, and speed density would compensate because of the change to MAP caused by the vacuum leak.

Not to say you didn't damage anything else.... did you check the MAP sensor, look for bent throttle blades, check to insure the IAT sensor is still there, check to make sure the elbow wasn't blown off the bottom of the TB where you can't see it.... etc.?