Hey folks new to the group I got me a Zj the other day and it's skipping/misfiring but it will blow air back threw the air intake hose and pop has a lack of power when doing this it does it on take of but you can put it in park or nutural and rev it and it doesn't do it any suggestion on what to replace or start thanks in advance

 

Well you've got a backfiring problem, check the cat to see if it's fowled. A backfire is caused by a lean running condition, so you'd be wise to check fuel pressure as well.

 

I had the same problem and the fix was a new ECM. The ECM cost me around $250 out of Florida.

Is it throwing any codes????

 

Only codes it throwing is maf sensor, crank position sensor o2 sensor I think that's it all the codes are sensor there are a few more I can't remember off the top of my head

 

There is a possibility your wiring harness is kaput. I have a 97 Laredo and it has same problem. You can wiggle the ecm connector closest to the engine with it running and see if it dies. The plug had a lot of stress on it and the pins in the connector get enlarged and make intermittent contact and the coil quits firing then lights back up and there goes the cat and muffler. Replaced ecm twice in 3 months then looked at connector. Ecm is ok, plug is shot. Haven't been able to find re-pin kit so I soldered connector and my jeep runs like a jeep should. If it fails again, I have a great gm 4.3 that's looking for a new home Hope this helps