put new headers, cat, and exhaust on my 1991 accord LX... didnt put the o2 sensor on when i did this. do i need the o2 sensor?am i lossing power??
if anyone can help that would be great.

 

the o2 sensor monitors the amount of oxigen in the exhaust system , once detected it sends a signal to ecu wether to richen or lean injector duration ..engine could be running richer or leaner that what it is suppose to ..if o2 is not in.. chk engine lite will come on you wont pass emissions

 

besides for the check engine light being on... is it hurting my engine? am i losing any power? could i gain any power if i put a new one in?

 

I guess You are aware of emmission. My car 1990 accord ex failed emmission
(hydrogen is very high) 6 times. EGR,pcv, plugs,fuel filter,antifreez replaced
cat only checked seems to be ok. hi can you give me any suggestion to reduce hydrogen. suppose to be 2.5 my car is 4.7. Time is running out.