# 1997 Maxima running rough... SES codes



## Spiers (Oct 23, 2010)

Hi, I have a 97 Maxima V6, 5spd manual. Has 191,000 miles. I just bought it today. It is running sort of rough...like a misfire. It drives good, I took it to autozone and here are the codes it shows:

P0325 knock sensor
P0110 air intake temp sensor
P0105 Map sensor
P0500 speed sensor

I have also noticed that sometimes the speedometer is not working...one minute it works fine and later doesnt work. That, and like I said acts like it has a missfire, and I think the muffler at the end of the tailpipe may be bad, rattles alot... Where do you suggest I start to track down the problem


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## rogoman (Dec 16, 2004)

Since you have multiple error codes, first check all the ground connections; there are several.


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## Spiers (Oct 23, 2010)

Since I am new to the car, would you care to share with me the locations of the ground connections... thanks a lot.


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## rogoman (Dec 16, 2004)

Here are some ground connections for the engine control harnesses:
- Two near the top of engine on driver's side.
- Three near the alternator.
- One near the fuse/fusible links box in engine compartment.


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## Spiers (Oct 23, 2010)

Update: Was checking ground connections, they looked fine - except I couldnt find the two near the drivers side top of the engine. But I noticed both the MAP and IAT sensors were actually unplugged. They were sitting on the connectors but not plugged in for some reason. So I plugged the two sensors back in, checked all other wiring, and found nothing else wrong. 

I then disconnected the battery for a short time. After reconnecting it, and starting the car, it was running "normal". It had a lot more power and wasnt misfiring -- until the car reached operating temp. Once it car warmed up, it started running like crap again. The SES came back on (flashing), took it to Autozone and only one code was shown at the time. Code P0306 (Cyl 6 misfire). What should I look for next

PS- I also noticed that after starting the car, the speedometer/odometer do not work at all, until I initially hit ~50mph. Once I hit around that speed, the speedo/odo start working just fine, and continue to do so until the car is shut off. And once the car is started back up, its the same thing all over again.


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## rogoman (Dec 16, 2004)

The code P0306 indicates that a misfire is occurring on any of the cylinders. It could be just a case of dirty spark plugs or possibly dirty fuel injectors.


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## cngarch (Sep 5, 2018)

Get yourself a multi meter and get on utube and type in checking knock sensor on your car. they do go bad but with small hands an a lot of cuts (the gaskets are stainless steel and will cut you) they can be replaced without taking the intake manifold off the engine($600.00).

Otherwise have the fuel pressure checked. On these older cars the fuel pump can trigger the knock sensor code. I have a 1996 infinity with 268000 miles and it runs fine but does have problems with vacuum leaks which can cause a lot of problems. misfiling, poor gas mileage, pcv valve codes. Diagnosis in 1996 was in it infancy and OBT2 codes were also. The problem is often far from what it says.

I have also had to take the intake manifold off to replace the valve cover gasket. A common problem. I have had the transmission fluid replaced every 75000 miles. (synthetic)

Speed sensor?


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