I had a major issue with my 2000 Civic HX. It started with the ECM code P1163 and P1164. I bought a new O2 sensor, but the check engine light came back on. I then noticed a crack in the manifold and bought a new Honda one ($600), but the check engine light came on again. So I took it to the dealership and they claimed I needed a new ECU, so I bought a rebuilt one, but the light still came on. I took it back to the dealership and they said I needed a new O2 sensor....again. I said screw it and had them replace it, but the light STILL CAME ON. I returned it to them AGAIN, and they told me the problem is I do not have the updated A33 ECU!!! This just did not make sense. Why would my car suddenly need an updated ECU when the car was built with the A32 (A33 is the newer version)? Does this make sense to anyone? With this logic, my PC may randomly decide it can no longer run on XP and I have to upgrade to Vista, even though my pc was built with XP.
ANYWAYS -

I kept this car for nearly a year, continually having this problem (although I did eventually figure out if I drove the car just the way it wanted, it would not trigger the CEL), 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 the car 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 if anyone else has this problem, they might like to know

 

Another lesson learned...don't buy a rare style car. They are much more expensive to buy new parts for and much harder to find used parts for. Hell, the oxygen sensor is over $450 at the dealership, and $270 was the cheapest I could find on the internet. I guess as long as it is running fine, they are great cars, but hope they don't break.

 

You get the money back and more in gas savings. Why double post?

 

just to make sure. This is mainly for later down the road when someone else is having a problem. When I was searching for information about it, it was near impossible to find anything, so I am attempting to post on every civic forum possible to save everyone the trouble that I had. I even thought about leaving my number as I now know more about those cars than any honda technician I have met thus far. It probably wasn't necessary, but I don't want someone to waste the time and money when they don't need to. Sorry if this has caused a problem.

 

The reason they updated the ECU is the same exact reason you needed a new one. The ECU was originally badly programmed and causing problems or something like that and they had to update it.

Your O2 sensor costs more because it is a wideband O2 sensor, not because the car is more "rare"... it works better and is one of the things that helps you get better gas mileage. Since the engine is lean burn, the ECU needs the most accurate Air/Fuel ratio readings it can get so that the ECU won't let the engine get too lean and blow up. The narrowband O2 sensor found on the other models just can't provide the accuracy that your engine's life depends on.

And about the PC's, they do randomly decide that they won't run XP... or anything at all for that matter.

 

I already knew about the reason for the cost of the O2 sensor, it just sucks that it costs so much in comparison (I believe they use something quite similar in some high dollar quads as well). And, yes I am perfectly aware of the reason for the ECU minor adjustment (which is actually not a completely different ecu, it is the same one with a programming adjustment, yet Honda will not reprogram the A32), but the reality is, the weight of the wheels were causing the problem the entire time. The new owners have had the car for a few months now, and have yet to have the CEL come on yet. I am pretty certain the new ECU would fix the issue, but it would still get less MPG than previously, and that is really just a patch to the problem....a $1200 patch if Honda were to install it. The reality is, these cars were just not meant to have any modifications if you want them to run correctly, even wheels.

 

What size wheels were on it?

What kind were they?

 

They were drag dc9 17" aluminum wheels with kumho tires that matched the original height of the old tire/wheel combo.

 

I'm not sure why heavier wheels would set a CEL. Other than the extra load on the engine was causing a rich condition all the time but, If more than normal weight set a CEL that you could never have a passenger or leave stuff in your trunk.

 

well what did you expect from those heavy *** 17" chrome rims?

really you have no one to blame but yourself.