# What the hell is wrong with this thing???



## BigityBalzworth (Feb 16, 2011)

Ok, so the car is actually an infiniti, but this looks like a good forum. I helped my cousin get a good deal on a '98 infiniti I-30 auto with about 180k. It ran good but cold, and as soon as we got it a changed th thermostat and it ran fine. about a week later he was driving cross country and the water pump went out. after having the pump replaced it seemed that a cylinder wasn't firing. he drove it back like that and is does drive ok once warmed up. When he took it to get it through emmisions they gave him the following trouble codes:

p0325 - knock sensor 1 circuit malfuntion (bank 1 or single sensor)
p1148 - closed loop control (bank 1)
p1168 - closed loop control (bank 2)
p0600 - serial communication link malfuntion
p0134 - o2 sensor sircuit no activity detected (bank 1 sensor 1)

I have swapped plugs, injectors, and coils around and the same cylinder is always dead. compression is fine. I have even changed the whole wiring harness after reading a TSB on broken wires/ failing harnesses. Also changed the o2 sensor. I'm really at a loss and could use some input. thank you...


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## LilleUlv (Apr 19, 2011)

Can I just ask a silly question? Did u Change the knock-sensor?


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## smj999smj (Jan 1, 2006)

It is a "silly question" because a knock sensor won't cause a misfire...and, if the engine is misfiring, it will set the knock sensor code. Check the compression of the incident cylinder. If the compression is good and it's getting spark, you could have a bad or inoperative fuel injector. Test the circuit with a "noid light." Check for signs of water contamination of the ECM. Check the ECM grounds (oxygen sensors and knock sensor, fuel injectors all ground though the ECM). You could have two bad front O2 sensors, causing the codes; circuits would need to be checked. As far as the P0600 code, I've seen it set on a number of Maximas with traction control and the cause has always been a faulty TCM. That said, bad ECM grounding can also play part in setting a P0600 code.


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## Jeff (Oct 17, 2002)

I was thinking ECM as well. If it's only one cylinder even after everything is switched around. 
Did you check the circuit coming in for both the coil and injector for that cylinder?


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