94 civic lx 5 spd problem

put aftermarket exhaust on and took out one resonator and put 2.5 inch piping...and now when its reved ovcer 3000 it pops real loud when clutch is pushed in like it backfires...what is this?

and my cars 3rd gear grinds when you push it in too fast but not if you push it into the gear slowly. could this just mean the gear oil is low???

i have the same problem as you in my 3rd gear. when i push it in to fast it grinds really bad.

i asked one of my friends and he told me the its probably the idle. it means its not synchronized correctly.

you can buy a new i think for like about $160 or something like that

Idle has nothing to do with it.

Paying $160 for a synchro is stupid, when you can get a whole tranny for around the same price.

IF you're grinding third gear while shifting, it's one of these things:
Synchros are getting bad.
Shifter forks are worn (probably, since they're aluminum in your tranny.)
Clutch is worn/misadjusted/warped.

Once you've figured out which thing it is, we can discuss your options for fixing it.

Once again, replacing it will almost always cost less than fixing it, unless it's something stupid... in your case, as is almost always the case with grinding gears, you're going to pay more than it's worth to get it fixed.