So I recently installed my Intake Manifold and I'm pretty sure it doesn't leak as I did everything right and tightened everything down according to specs. But this could be unrelated to the install because everytime I race my car and shift to 3rd I get a loud backfire. I installed an X-pipe a long time ago and used a C Clamp to connect it to the header because one of the bolts broke and maybe that is starting to leak, I should get around to getting new headers. What causes a backfire though any suggestions what to check. I don't really get performance lose just the backfire than everything is normal. Timing is at 14* and I run 92-93 octane. Thanks.