I have a 2001 Civic LX with D17A1 engine and have both O2 sensor codes P0135 and P0141. Both codes set with in 10 seconds from reset of ECU. Both codes are for the O2 sensor heated circuits. If anyone has run across this before help would be appreiciated.

 

How many miles? Any cracks or leaks in the exhaust? How long has it been doing this? Have you done any recent work to the car?

Could be bad sensors, connections, ECU, etc.

Anyhow, the troubleshooting procedures for those codes is rather lengthy. Sorry, but I simply do not have the time today to draw them up. Maybe some time within the next day or two I can.


Aside from that, you should invest in one of these. http://www.helminc.com/helm/product2...C01&itemtype=N

It's the best manual you can get for these cars. If you don't want to buy a new one, search eBay or craigslists for a used one.

 

Timing belt went out and took 4 valves with it. Have engine back together and runs fine but will set these 2 codes with in 10 seconds. I have the manual you show and went through the troubleshooting for each code and found nothing. Sent ECU out for testing and they found nothing. I am thinking it is something in wiring connections but can't find. Does anyone have an ECU pinout guide for this vehicle?

 

Interesting.


I do recall someone on here having an issue where the wires were stretched and one had broken, but the rubber/plastic covering never separated. But to have this happen to two sensors at once? Not very likely.

Have you looked in your area for a parts car? I'd try swapping the sensors just for *****-n-giggles. I don't know why they'd go bad just because the timing belt snapped and ruined some valves, though. Very strange. The connections are tight, though? No loose terminals or anything?