I am glad this forum is available as a resource. My '99 Max GXE just gave me the dreaded MIL. I retreived the codes 0702 and 0201. From viewing posts here, I believe I have an O2 sensor problem. Can anyone confirm that Bosch would be a better replacement than OEM? Should I replace both side 02 sensors, or just the one? Also, is the 0201 a result of the first code, or is it a separate problem with the ignition coil? Thanks in advance for any help.

 

not sure if its an O2 sensor problem but.. barry had a simular problem.

http://forums.maxima.org/showthread.php?threadid=37987

 

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

 

Diagnostic Trouble Code 0201 indicates a problem with the ignition coil and power transistor. The ignition signal from the Engine Control Module is sent to and amplified by the power transistor. The power transistor turns on and off the ignition coil primary circuit. This on-off operation induces the proper high voltage in the coil secondary circuit.

The malfunction is detected when the ignition signal in the primary circuit is not entered during engine cranking or running.

The items to check include
- Harness or connectors (the ignition primary circuit is open or shorted.)
- Power transistor unit built into ignition coil
- Condenser
- Crankshaft Position Sensor (REF)
- Crankshaft Position Sensor (REF) circuit

A misfire on any individual cylinder should set a code, and a problem with the CPS should also set a code.

I would have expected to see DTC 0201 along with one of the following DTCs.
0407 - Crankshaft Position Sensor (REF)
0608 - Cylinder 1 misfire
0607 - Cylinder 2 misfire
0606 - Cylinder 3 misfire
0605 - Cylinder 4 misfire
0604 - Cylinder 5 misfire
0603 - Cylinder 6 misfire

You didn't get one of these "companion" DTCs, and that is puzzling. Maybe one of them will show up in the next few days.

 

Thanks to Daniel and SprintMax for your feedback. With only 43K on it, I'm a bit disappointed. If I wanted problems like this, I could have bought a VW!

I'll look out for a "companion code" to the 0201, and post my results when I or the dealer works it out. FYI, within the last 3 weeks, the engine wouldn't turn over on one occasion. I just cranked it, had to finally jiggle the throttle body to get it going. Weird. Hasn't happened again. Getting about 22 mpg, with mostly 3.5k shifts, and the occasional Nascar red light adrenaline. Alot of cruising at 75-80.

Any possibility the K&N air filter is an issue. Should I have just stayed with the Nissan paper?

Jeff

 

I doubt it.. i have a K&N filter at the end of my CAI and i shift at 6k from stop light to stop light.. so i doubt that anything like that caused it

 

I've heard stories about aftermarket air filters deteriorating and sending fragments of filter media downstream where they got snagged in the Mass Air Flow Sensor and caused all sorts of trouble.