I’m installing a new zzp long tube on my lsj, (switching from a cheap eBay ripoff) and the o2 sensor bung on the new header seems to be a different thread pattern than the others on the zzp down pipe. Thoughts??

 

When I installed my shorty header I did notice the thread being a bit tight. All i did is trace it and clean up the threads and it was fine. Do you mean a different thread count & pitch? Because it should be the standard m18x1.5. If it was ZZP I doubt it's the wrong bung, but mistakes do happen.