O2 Sensor/Code 1a

[sebastianblue]

1990 Honda Civic Si 1.6L, I've been having code 1 pop up since I bought this car, the previous owner was mechanically minded and said he had had similar problems. Replaced it first with a NGK O2 car drove well with it for a week then the code came back. I went back to Lordco and asked what other brands they had for Honda. They gave me a Bosch O2 which they said was actually the OEM part. Same thing, got a week out of it and now the code is back.

The cars performance is altered by about 100-200rpm but basically the engine light is always on once the car is warmed up. I have read about similar problems pertaining to this year car and O2 sensors, Bosch was recommended and I don't see how these both could be incompatible with the car. I called my local dealership and they quoted me $275 for an actual Honda sensor, I don't want to try that unless I have to seeing as how I bought both previous sensors for under $100.


Basically I'm asking for any other ideas, could it be the plug? I'm at a loss for ideas. Anything would be helpful, please and thank you.

 

[XpL0d3r]

Yeah, I'd follow / check the wiring and inspect the plug as well.

Also make sure it's code 1 you're dealing with and not code 10.

 

[lethal6]

Hondas are notorious for rejecting aftermarket O2 sensors. With sensors, fluids, and ignition stuff, OEM should always be used. By the time most people get done messing around with a couple different aftermarket sensors they end up near where the price would have been for the OEM one, especially if you factor in the time to do it which may not be a monetary value if doing yourself, but it accounts to something at least.

Not saying that one of your sensors may hold, but I have seen it more times than I can count on my 2 hands.

 

[sebastianblue]

So are you saying I should just buy the dealerships sensor? I am doing it myself and own the socket so it's really no problem to throw them in. I'm not sure how reliable Lordco is but they said the Bosch sensor was OEM. Since it rejected it I assumed it was the plug.

 

[lethal6]

I believe the OEM sensor is NGK brand, if not it is DENSO. Bosch is a great brand but usually left for German vehicles from the factory, from what I have seen.

I would check all the wiring and make sure it isn't just a bad plug or melted wire that is causing all of this. Then, I personally would take the aftermarket ones back and get an OEM. You can find them online at various Honda parts wholesale websites if you need to save a bunch of money over walking into the dealership. Being from the dealership side of it, I hate to say that but the wholesalers don't have as much overhead as a dealer, nor do they have all the money that goes into brand training their employees. All that adds into the prices of the parts and labor.