i have 98 civic hx, the check engine light came on it was a p1163 O2S1 slow response. i looked at it for awhile, i had found a long crack on the manifold in between the middle runners all the way to the sensor so i pulled the mainfold out and sensor and welded up the crack, the sensor was also replaced with one from merles (local parts store) which is a little better then say checkers, but it was not a factory one. i drove it, light still came on, same code i then ohmed out every wire from the sensor to the pcm all were fine, i found a tsb which stated to replace the pcm with an updated one but they were almost $800, so i figured i would try a used one didnt think it was possible for all of them to have that code, so i tried 3 different used ones same code came up. is there any other thing that could cause that problem before i go to having to put in an expensive o2 sensor or a processor. the only other thing i was thinking it could be was a pin fitment issue where it was intermitanly backing out, or another pin hair crack in the manifold i could not see. i dont remember coming accross this issue when i was working on honda's more consistanly than i am now.

 

You may not have completely fixed all exhaust leaks.

 

thats what im hoping for at least.

 

anyone else have any insight?

 

bump

 

ttt

 

Don't they have some type of dye you can put into liquid gas, that when changed into emissions, you can use a black light and see it? I don't know. Thought I heard of it, but I could be blowing smoke.

 

if you are refering to that as for finding an exhaust leak i have never heard of it, i have heard of using a smoke machine which is basicly fog to find a leak.

 

Right, but thats for a vacuum leak, it would do nothing to solve an exhaust leak, except exacerbate the problem.