does a 79 zx have an 02 sensor? bcuz i dont see one on my car...

 

yep... all fuel injected Z's have O2 sensors... 99.9% of all fuel injected cars have o2 sensors.... it's a big part of the EFI system.

Your o2 sensor should be visible by looking @ the exhaust manifold from the top side, by the brake fluid resevoirs

 

*** cuz i hollowed out my cat and it has been running funny, i was running the same b4 but since i hollowed it out it has bee a little worse

 

cat is AFTER the o2 sensor... unless you are backfiring like a bitch, "hollowing out your cat" doesn't have any effect on your o2 sensor.

 

mmk well then it is running like ****. it boggs in low rpms and wants to die,, but not all the time, when it does do it, is below 3k rpms anything after that it runs great
just really rich..

 

Wrong... not all of them (or all fuel injected cars for that matter) have an o2 sensor. My car (1980 Non-California) has no o2 Sensor and didn't come with one. My 81 did have an o2. Pretty sure that they didn't come in until 81 on the Z. I also know for a fact that my buddies 79 doesn't have one and didn't come with one. Sorry

 

interesting... I've seen 280z's in the junk yard w/ o2 sensors... huh

 

Ya, some 280Z's do. All of the 1975 Z's don't. I think CA models got them in 76. Anyway, there's a mixture of them with or without up untill about 1980. The O2 sensor does help a lot though in keeping things the right mixture for power and economy.