0702
Diagnostic Trouble Code 0702 points to a problem with the three-way Catalytic Converter.

The Cat is one of the principal components of the emissions control system. The Engine Control Module monitors the signals from the two front Oxygen Sensors and the one rear Oxygen Sensor. The signal frequency of each sensor indicates something about the condition of that sensor. A comparison of the frequency of the front sensors with the rear sensor indicates something about the condition of the Cat.

This malfunction was detected when the ratio of the signal frequency from the right bank front Oxygen Sensor to the signal frequency of the rear Oxygen Sensor exceeded a critical threshold value. This indicates that the Cat does not have enough oxygen storage capacity. The right cylinder bank is also called the rear bank. It is cylinders 1,3,5. Possible causes of this DTC include ...
- Three-way catalyst
- Exhaust tube
- Intake air leaks
- Fuel injectors
- Spark plugs
- Ignition timing




Could the fact I have no catalytic converters account for this? How serious of a problem is this and what do you recommend I do next to have it fixed?

 

had that for a while. front heated o2 sensor. also code 0420. just reset it and see if it comes back. i've heard of freak codes. also with it accompanies a ks code.

 

Yup got a KS code too!
Can this problem lead to a loss of HP/torque? Any idea of what to do next?

 

loss of a lot of low end power. your car is in safe mode and the timing is retarded. u can try replacing the o2 sensor first because that may also be fals triggering your ks. read the stickies, lots of info there. spend a good hour reading and you'll be set. i myself just dont have money to buy those sensors. woe is me.

 

After re-setting the ECU and driving 40 miles today all I have now is code 03 04- the knock sensor. You're right, there is a loss of low end power: I hate how when I accelerate, my MPH don't go up in proportion to the RPMs. Also, isn't it bad for your engine to be running with retarded timing?

Knock sensor? Mass air flow sensor? Oxygen sensor? Which of these should I be looking into as the culprit? Looks like I'll hafta take this to the Nissan stealership to get investigated if I these codes comeback. I hope they're not ticked off that I have no cats.

 

Sounds like my best bet is a new O2 sensor...agree or disagree?