01 Pathfinder (VQ30) ECU mystery codes. Please Help

[94q45t]

My 01 Pathfinder (104K miles, services up to date) has started running very roughly intermittently and occasionally stalls. The check engine light has come on. When it runs rough, the CEL blinks. When it runs smoothly, the light stays on steadily. OBDII is returning these codes: P1135, P1320, and P0464. These are not in my books or my mechanic's books, and his diagnostic tech support people are having to research them, too. I had a similar thing happen to my 00 Maxima, and no one ever figured it out.

Has anyone dealt with this or know what the codes mean? thanks!

[NISTECH]

on both your max and this vehicle the coils are the problem. likely only one of them but without a misfore code its impossible to isolate which one it is. The check engine light flashing is signalling the misfire is bad enough to damage the cat convertor.If you sustain the flashing light long enough it will through the code. I think spec is 20 seconds. Then you can isolate which cyl it is missing and replace just that coil. The code will be p0301 to p0306 each one indicates the direct cyl. for example p0302 indicates cyl #2. P0303 indicates cyl #3 and so on. The p1135 information can be found in the sticky at the top of this thread. P0464 is a Evap system code. I dont know for sure off the top of my head but I think 464 is either purge control or vaccum cut. In any case none of the 3 codes are related so each needs to be addressed seperatly.

[NISTECH]

BTW you dont have a VQ30 you have a VQ35DE.

[94q45t]

Thanks, I found that out. I have a VQ30 in my 00 Max.

[94q45t]

Thanks for the help. One of the codes was for the cam timing sensor. Evidently whien this malfunctions, it also can cause the coils to throw the 1135 code. My course of action is to reaplce that, then clear the codes and see if that cures the problem. Based on your advice, I ought to be abe to diagnose the coils whilst I'm at it. Much apprecation.

[NISTECH]

You got your codes confused I think. Here is what they mean.1135 intake timing sensor1320 ignition signal primary [coils]464 Evap VCV/purge valve.

The cam sensor going out will not cause the pinging and certainly wont cause a code 1320.

[94q45t]

I did get them backwards. I was on the road and trying to post from memory. Anyway, this is what drives me crazy about Nissan codes. The dealer says the P0464 code is the fuel level sending unit, which makes sense because the fuel gauge just started going bonkers when the fuel level falls below half tank.

On the other codes, the crank position sensor is listed by Alldata as a potential cause of both 1320 and 1135. Then again, any of these can be caused by bad harness connectors, so I can see a slippery slope of expensive repairs if I don't arm myself with some info early on.

What really concerns me is that all three codes popped at the same time as did the fuel gauge malfunction. I wonder of thereal problem really is in the harness and not the individual pieces? Have you ever seen that?

[NISTECH]

Not that often but it has been known to happen. I have yet to see it on a pathfinder. your Max was more common to have the harness issue.

Like I said I wasnt sure on the 464 code. it is related to evap though. The fuel sender reading is used during Evap leak check. It looks to see if the gauge is between 1/4 and 3/4 tank to do the test. If the reading goes out of range it will throw the code.

[94q45t]

Well, the intake valve timing control is now the official diagnosis, and it seems to have solved the problem, though the explanation was a bit bothersome. The old part had some sludge build up likely from insufficient maintenance (we bought it used, we're an every 3K oil change family). If true, there might future trouble in store. Are there any additives that might reduce the sludge problem? Thanks!