Hello all,

I just did some pretty involved work on my civic (2000 EX d16y8). Replaced clutch, rear main seal, oil pan gasket, oil pump, and water pump gasket. To do all this I had to drop the exhaust. I disconnected it immediately after the manifold and also immediately prior to the muffler next to the right rear tire. For a moment during the process the weight of the exhaust was hanging from the wiring of the rear O2 sensor. As a result the spades came out the back of the wiring connector when it came loose. I was able to reinsert the spades into the back of the connector and it seemed to go back together fine.

Now everything is back together, seems to be running smooth with the exception of a CEL, which is being caused by codes 135 and 155 (both O2 sensors). Anyone else had this happen following dropping a significant portion of the exhaust?

Also, does anyone have any tricks for getting the alternator belt tension right? stupid thing is in a terribly awkward spot, I can't seem to push it out enough to get that last little bit

Thanks!

 

Heater codes for both sensors often mean that fuse 15, which supplies the heaters, is blown. The wires could be damaged and shorting out where they enter the sensor. Also check for the known problem of the harness fraying on the intake manifold bracket.

Code 155 should not occur on a Civic since there is only one sensor bank. The corresponding code is 141.

 

I obtained the codes via the code reader at advance auto parts, so I'm reasonably confident in the 2 codes being accurate. I will check the fuses

 

where is fuse 15 located?

 

In the underhood fuse box, I believe

 

so far I have not found any blown fuses and I have checked all the 7.5A ones (I believe fuse 15 is 7.5A)

 

When you turn the key on (no need to start), is there battery voltage to the sensor heater wires? I think the wire in the harness is black-yellow. The heater wires in the sensor are the two that are the same color, usually black.

 

just got back from a trip from OH to NC and got excellent fuel econ (~40 mpg) so I doubt very much that the primary O2 sensor is malfunctioning. So it must be the secondary O2 sensor (the one behind the cat) which apparently only exists to verify the function of the first O2 sensor and the cat. will look into those wires tomorrow