Quirky code 44

[MashimaroNSX]

Hi, looking for some input. So just a backstory before I get into the symptoms. I recently changed my o2 sensors and was driving it for approximately 1 month until I realized it was driving funny. So a little search on prime told me that the wires might have been crossed and when I went under the car they were indeed crossed so I attached the front sensor to the back plug and vice versa. Right now the symptoms feel like I have turbo lag (though my engine is naturally aspirated) where power feels lacking and then all of a sudden it surges just like a turbo. It takes awhile but then sometimes a CEL comes on and things seem to run fine. When I pulled the codes it was a 44 and upon researching it could be the rear o2 sensor or fuel related? Also someone told me it could be a leaking exhaust which brings me to another background where a long time ago when my car was brought into Honda for an oil change they mentioned that I had an exhaust leak. However I wasn't able to locate the leak they were mentioning and just kept driving it all these years without any symptoms. Could driving the car with the o2 sensor wires crossed have messed them up?

 

[asylum]

A code 44 could be related to your O2 sensor (even if it says "fuel supply"). I would just disconnect the rear O2 sensor. It will throw a cel. But if the car run fines, without the hesisation you described, it is due to your O2 sensor.

I had this kind of hesitation and this was due to O2 sensors. When I gave gas, the car took sometimes 1 second delay before accelerating.

If the problem is not solved, come back and we will inspect further (fuel pump & injectors). But, as you messed up a bit with the O2 sensors, let check this first.

 

[Old Guy]

Just to confirm, we are talking about an unmodified car with all OEM stuff?

How do you switch the front and back O2 connections? I am not familiar with the pre OBDII O2 connections. Aren't the connectors in the same location as the primary O2 sensor location on the OBDII cars? The 1991 service manual shows the O2 connectors on the top of the engine at the front and back of the cam covers. I am confused by the reference to going under the car to check the connections since the connections appear to be 'up top'. If you mean that you installed the front sensor in the rear location (and vice versa), as long as the cables were long enough and the connectors fit, the switch should not cause a problem. Its more likely that if you had to 'stretch' a wire to make them fit that you may have created an intermittent connection problem.

The service manual sets out a procedure for testing the O2 sensor using a voltmeter. This will give you confirmation of whether the sensor element is dead. However, the test procedure is a bit of a hassle. If, as Asylum suggests, disconnecting the O2 sensor puts the ECU into open loop mode, and the car works better in open loop mode, then you likely have a bad sensor or a bad electrical connection between the sensor and the ECU. Since you recently changed the sensors, I would first be looking for bad electrical connections rather than a damaged sensor element. No point in putting in a new sensor if the plug on the engine wiring harness side is damaged.

A leaking exhaust system might cause the O2 sensor to read lean. However, the pre OBDII cars have the sensor up stream of the cat. If the exhaust leak is downstream of the cat (in the muffler / exhaust system) it is unlikely to affect the O2 sensor operation. If the exhaust leak is at the exhaust manifold flange or between the O2 sensor and cat, that can cause the sensor to read lean resulting in the engine running rich. However, exhaust leaks at the exhaust manifold flange or pre cat are usually fairly easy to hear if they are admitting enough air to mess up the O2 sensor reading. Also, really significant leaks at the exhaust manifold flange don't last that long because bad things happen leading to a trip to the repair shop.