KA24DE acting wierd. missing a cylinder?

[jpnissans13]

Ok so i have a 91 s13 with a ka24de and i have a weird problem. sometimes when i start the car, the car shakes a bit and makes a boging sound when i drive off. like the exhaust would have a hole i it. and its lacking power at the same time. it goes away after a while. and sometimes it happens when im driving. it would be all normal and then all the sudden it would start sound like the exhaust would have hole in it + it loses power. accelerates like crap. what would cause that? plus to all that when its not doing that when i shift a higher rpm's it makes a pop sound like a back fire. seems more like its some where between the muffler and cat.

+ when i seafomed the engine there were smoke coming out of he engine bay. exhaust leak?

Thanks for any help!

[nismogarcia]

Your Cat might be plugged up

[jpnissans13]

would that reduce power?

[PapaSmurf2k3]

yes, it would, but it is VERY rare, and it would not be intermittent.

Check over the car for exhaust leaks, and also look for corroded/half broken engine grounds.