The check engine light on my daughters 1998 Maxima stays on & the car runes fine as long as the light is on. Once a week or so the light will go off & then the car runs like **** & dies. Once the light comes back on, it starts running fine.

We checked the codes & found P0325 & P0443. I know the 325 is the knock sensor but I have also heard that it will NOT set off the light if that is the problem. Is that true?

The P0443 is something about the Evaporative Emission Control System, can anyone give me details on this? Will this set off the light? Will it cause the problems stated at the first of this post?

 

well the knock sensor will throw a code cause it detects knock from the engine wich is BAD lol. the knock sensor is located underneath the intake manifold wich is a good 4.5 hour job if you know what your doing. the evap code is probably a small leak probably from a bad gas cap. try replacing the gas cap and have the codes deleted and see if that fixes the evap code. you can also delete the codes from disconnecting the neg. battery cable for about 10-15min and push down the brake for about 15 seconds and let it reset the ECU and it should erase the codes and if it comes back on check to see what codes are present. good luck

 

I will try the gas cap idea...it would be too easy for that to be the problem

So when I disconnect the battery for 15 minutes, do I press the brake for 15 sec after hooking it back up or what?

 

you hit the brake pedal after you disconnect the battery to drain the rest of the power out of the ECU so it can reset. also you would be suprised on how many of the evap emission codes are caused by loose or bad fuel caps, but what do i know ive been a auto mechanic for 8 years.

 

Thanks for the help...I turned this info over to my x-wife since it will be 2 more weeks before I have my daughter again. She is planning to try a new gas cap.

 

There may be two or more separate problems, this can be bad MAF: "the light will go off & then the car runs like **** & dies." When this ****problem is ON, to diagnose, take MAF connector out ... engine behaviour should become near normal (2.2k rpm ceiling). If this helps, then new MAF may help. Try cleaning it before swap.

Some MAF links from this page: http://www.cardomain.com/ride/748507/9

 

Thanks reiska...I will try cleaning the MAF this weekend when she comes over. It has been acting up on her alot...

Gas cap is ordered...should be in today!

 

make sure and buy the maf cleaner from the part store i believe a brand called crc makes it. keep us posted

 

I have a can of it already...I clean the MAF on my Silverado a couple of times a year...I will do hers in the morning.

I haven't looked at it yet, But I am assuming it is a simple job with just a couple of clamps holding it in the middle of the intake tube...Am I correct?

 

yea your correct its simple