so here's the dilly.

i have a 2000 civic hx, 5spd.
About a month ago, it started throwing a CEL code, ( P1163 ) which is the oxygen sensor. So i went on eBay and bought myself a new oxygen sensor and replaced it and then resetted the ECU, and the code went away...

Then I drove from NY to NC, then from NC to GA...now i'm still here in GA, going back to NY in a week..the car drove okay for the most part, but i did experience some weak engine response when tipping on the throttle in low rpm's and sometime in high rpm's...I was thinking it was maybe the spark plugs or fuel filter causing this ( hesitant acceleration ), so i replaced both spark plugs and fuel filter...it continued to do it, but not as often...

Today, the car threw a P1164 ( air/fuel/ratio, whatever code ) and the guy said to try unscrewing the gas cap and screwing it back on, and so I did...and the code went away....then about 2 hours later, the code came back on!

What seems to be the culprit for this? I would like the engine response to be better and to get rid of that hesitant acceleration i seem to get at times, and to get rid of the friggin CEL's!

thanks guys!

dan

and PS, its not the oxygen sensor..i already replaced it with a new one...and the hesitation problem was present before the old one went bad..

 

anyone????

 

how did the plugs look when you took them out? most importantly, did they all look identical in color and condition? you could try closing the gap on the new plugs to about .030 and see if it clears anything up. is the car modified at all? how many miles on the car?? more info!

 

they all looked a little identical...one of them had a little white stuff going on, but looked fine for the most part...I bought the NGX type R spark plugs, pre-gapped to 0.04

the car is pretty much stock now, and about 130k on it

 

I know it may be a bit too late, but I had the exact same problem. I replaced the exhaust manifold/cat ($600), the oxygen sensor twice (was told the aftermarket ones were not good enough although I don't truly believe this), replaced the ECU with a remanufactured one (turned out not to be true either and actually am selling the reman one for $150 if you need one although I paid 300), and it still kept throwing the P1163 and P1164 on a regular basis. Eventually I learned if I drove the car the way it wanted to be driven then it would not click on quite so often.

 

I kept the car for nearly a year, continually having this problem then finally got sick of it and sold it. The new owners did not want my 17" alluminum wheels that I put on it and has never had a problem since. It turns out my aftermarket wheels were a little heavier than the originals and were causing a problem for the computer. Just for future reference if you still have this problem. The O2 sensor on these HX's are extremely extremely sensitive to just about any change you make...they are a 5 wire unlike the typical 4 wire of most cars. They breath the engine air as well as the outside air, which helps the car determine exactly what mix to put in the cylinders, hence one of the reasons why they get such phenominally good gas mileage.

 

Oh, forgot to tell you I had the exact same car you describe...2000 civic HX standard