ruiqiangli

I recently have this black MAXIMA, 1999, auto, already have 163K miles. It runs not so smoothly, so I change the oil, the gear oil, and balance the tire. I also change the spark plug by myself, clean the TB. Now the car runs much better!

But there is a thing trouble me so much. The "check engine light" is always on, never go away. It even flash when the engine works above 3500. When it is below 3500 the light will stop flashing but still on.

Then I found this great website, so I try to read the code and got it. It is: 0701,0201,0304. I try to clean the code, and the light for the first time went off! But as soon as I drive the car, the light come back again!

What else should I do? I love this car, want to fix it by myself, but now I can't find out what is really going wrong! I can start the car very easy, drive above 65 MPH, so I don't think it's the ignition problem, or spark plugs, is it because of the Knock Sensor? Should I change it? Or the gas not good enough? Or other problem? Really want someone could help me! Thank you very much!

Hi！After I use the screwdriver to get the code from ECU again, it is some change! The first code become 0605 instead of 0701. The code is " 0605 - Cylinder 4 misfire". The rest code is the same: 0201,0304. So my guess is, there is more than one Cylinder misfire before, and since I changed all six spark plugs, there only one Cylinder-4 is misfire. I will check cylinder 4 carefully and hope to get the car fixed. Thank you all guys! It is very nice that knowing someone is behind you and support you!

Hi! Me again! More things to report! I switched the ignition coil at cylinder-4 with cylinder-6, and still get 0605, so my guess is ignition coils are fine? Then I changed a new knock sensor, the code 0304 is gone!
But the 0201 and 0605 still show up! Just in case(and the car need it anyway), I changed the fuel filter today. There are one time that I can drive without any code, then code "0505" showed up once, now it still show "0605" and "0201". What else can I do? I already put 91#gas in with the Redline-sl 1, should I put some injector cleaner in the gas? Or I should buy a injector for cylinde -4 anyway?

I am confused again!

Need help!

98maxaholic

well, its definately not the knock sensor causing your problems, you are having a multiple cyl misfire..im thinking your primary ignition..but wait a few mins...im sure more people with greater knowledge than I will chime in!! good luck!

Slamrod

iTrader: (11)

Dirty injectors, run a few rounds of techron through her and theres a good chance itll solve all those codes. Better gas would probably also help.

DennisMik

iTrader: (2)

The P0201 is a fuel injector on cylinder 1. Try running some fuel injector cleaner and maybe you'll get lucky. But if you decide to take the fuel injector out, even to just look at it, get new o-rings for it. Old o-rings are almost guaranteed to break when you re-use them.

P0304 is a misfire on cylinder 4. It is probably a bad ignition coil. You can switch the coil with cylinder 2 or 6 and see if the 304 code changes to 302 or 306. FYI, when you see the check engine light flashing, that means that the engine is mis-firing at that particular time.

The P0701 is the automatic transmission. Make sure the oil level is at the full mark.

ABIGBRAIN

iTrader: (1)

What method did you use to get the codes? Scan tool or screwdriver into the ecu (and count the long and short flashes)?

If you used a scan tool Dennis' explanation is spot on. However, if you used the screwdriver into the ecu then those code numbers you have take on a different meaning.

0701 - multiple misfires
0201 - crank (reference) sensor
0304 - knock sensor

Andy

ruiqiangli

Thanks for your help! My reacting is just like you said! Hope I can find out why!
Have a good day!

ruiqiangli

I will take your advice and have a try! Can I clean the injectors myself? Now I am use redline sl-1 in the gas, hope later will work better! Thanks!

ruiqiangli

Sorry for my poor english, I didn't make it clear! The code is not read from OBDII, it's read from the ECU, from the light flashing. So it do not have "P" before the number. But still thank you for trying to help me out! I will try to clean the codes again, and see what will happen this time! Thanks again!

ruiqiangli

Thanks Andy! I am use the screwdriver to get the code, so your answer is right! But since I can drive the car easily, I am not sure it is a " multiple misfires" problem. I will try to do screwdriver again to see will the code change. Report later! Thank you very much!

ruiqiangli

Hi! After I use the screwdriver to get the code from ECU again, it is some change! The first code become 0605 instead of 0701. The code is " 0605 - Cylinder 4 misfire". The rest code is the same: 0201,0304. So my guess is, there is more than one Cylinder misfire before, and since I changed all six spark plugs, there only one Cylinder-4 is misfire. I will check cylinder 4 carefully and hope to get the car fixed. Thank you all guys! It is very nice that knowing someone is behind you and support you!

njmaxseltd

iTrader: (19)

The 99's are notorious for bad ignition coils. But since you have a crank sensor error as well, change that first. If the misfires continue, consider changing the coil packs.