2000 civic si b16a2
215,xxx miles

Im not much of an expert on engine internals so bare with me. My cylinder 3 went "shot" sounds like a wrx. I ran a compression test it was like at 50psi or something. I tested the injectors they were fine. ran a leak down test and it doesn't sound like anything was leaking. ran the codes before cylinder went shot and o2 sensors and catalytic conv. came up (forgot what the codes were).

I did some research but couldn't find a definite answer as to what can cause this. it seems others came across the same issue.

could it be that my rings are worned out?
my other assumption is that my injectors are good but can be leaking causing me to run rich?
or burnt exhaust valves?

there can probably be other possibilities but if anyone had this issue could give some input i'd appreciate it a ton!

 

What were the PSI numbers for all 4 cylinders?

If cyl 3 has very low compression compared to the others, then repeat the leak down test. You must have just missed hearing where the air was leaking.

Did the timing belt snap or skip some teeth?

 

I only ran a test on cylinder 3. decided im not even gonna worry bout it anymore! just gonna take it apart. rebuild my head and get a b20 bottom end. thanks for the reply tho.