shadowoffair

Hello all and thanks for your help and input ahead of time.
To the meat and cheese. I've got a 04 350z with 98k miles. only mods I know of are a stage 3 clutch, some Invidia HFC's, and a K&N filter only.


The first problem I'm having is a/f mix codes. I get P1284 and P1273. The codes are for a lean and rich mixture on the two different banks. I don't understand this...I have replaced the passenger side o2 sensor which took care of the p1284 for a while but then it came back. This tells me that the sensors are doing their job. I hate to throw parts at it till its fixed because that can quickly get expensive. I have also read that the only way to get rid of the messages are to have an uprev tune done. I wanted to see what the Z community said before pulling the trigger on that. I have no vacuum leaks and I just replaced the spark plugs as well as the #1 coil pack. I believe this is killing my fuel economy since when I first got the car I would get 25+ mpg highway, but not any more. Around 23mpg highway only...

Pending fix. Coil pack causing rough idle and improper combustion.

The second and mechanical problem I'm having is with my tire pressure sensors. After about 30mi of high way driving the low pressure light comes on. A simple power down and engine restart makes it go away till I hit the 30mi+ mark again. I'm sure I will just have to get the 4 sensors replaced since they are over 10yrs old..

Fixed bought new ones cost around 400 at the dealer..


The third and final mechanical issue is with starting the engine. 99% of the time it cranks up right away on the first try but after 50 or so starts it takes 3 tries to successfully start the car. It will crank over hard during the 3 tries but not run. I was sitting at a stop light one time and it died randomly. After looking up the obd codes I got 3 msgs for the cam sensors and a cam sensor circuit code. In the end my findings resulted in new cam and crank shaft sensors. Now when it randomly decides to not start on the first try it throws no codes whatsoever. This does not bother me as much as the other issues but I thought I would ask.
Z community research says its the NATs computer... (fails to sense the chip in my key). Friend and Nissan tech said I had internal codes for a (no key signal) bought a new key and fob from dealer 200 bucks later still not fixed. I just live with it, kinda embarrassing when it random "no start's" in busy parking lot though...


I plan on taking it to Nissan soon so they can look at it but I wanted to try some Z community help first.


Thanks for you time everyone. Cheers

bealljk

iTrader: (13)

I would look into replacing your crankshaft position sensor to complete the trifecta of sensor replacement. Do the throttle body relearn procedure after you replace the crankshaft position sensor (it's about at the 6 oclock position on the bell housing of the transmission, near the slave cylinder - very easy to get to/replace).

I'd also pick up a can of MAF sensor cleaner and clean your MAF sensor.

Yeah, replace the TPMS - I think mine lasted 6 years so you are far ahead of the curve...

Update the thread as you progress...

shadowoffair

I have replaced all 3 sensors, both cams and the one crank. Like i said after i got the Codes pop up for the cam sensors, all other reports in my research said change the crank with the cam sensors. One thing to share though. When i did replace my crank sensor i noticed that there was no o-ring on the sensor! so when i pulled it out all i could see was black dirt and debis in the hole. I cleaned out as much as i could but it wasn't perfect.

If you say re-learn procedure are you referring to the ecu reset? If so, then yes I have done that quite a few times but no lasting fix.

I was told not to spray or touch anything on the MAF as it damages easily. So im apprehensive to do so..

I think im gonna take it to Nissan shortly at least just to ask questions.

bealljk

iTrader: (13)

no, it's not the ecu reset ...

http://www.technosquareinc.com/350reset.htm

They make MAF cleaner and it's pretty straight forward...I have a few MAFs sitting in the garage...I'll send you one if you fork it up...I clean mine (despite it's obsolete-ness) and the GF's murano MAF every time I change the filter.

shadowoffair

Well thanks a bunch i didn't know there were that many different reset procedures for the 350. I just screen shotted all of them and ill be performing them tomorrow. ill keep my fingers crossed Ome of them work.

I'll find some MAF cleaner if you say it could help, heck shoot me a pm if you wanna cut me a deal on one. But im pretty sure my MAF is just fine. I actually did a ecu reset with the sensor disconnected once and i could tell a difference. I reconnected it and did another ecu reset and everything returned to as normal as possible.

shadowoffair

UPDATE
After driving for a couple more weeks with no new ideas and the same lean and rich a/f codes being thrown under the SES. As a reminder I do not have any FI bolt on's. So all the reading that I had done dealing with out of wacked a/f mixtures was for ppl who had TC's and SC's. I was gonna give it to nissan to look at (which ill still probably have them do) but im less inclined for this issue since I've had a bit of a breakthrough.

Anyways a G35 owner and buddy of mine ran across something in his search to help me figure it out. So before you go crazy throwing money at parts try this. My buddy found it on a G35 forum and txt it to me so ill copy and paste.

In quote: "Those of you who are having the issue with code p1283 I have figured it out!

Originally thinking it was an o2 issue I replaced them. Code was still present so I checked for vacuum leaks exhaust leaks etc. nothing I cleaned maf and car was performing better. Code came back. Then I thought my ECM was going bad? Did a little research and I mean a lot by that talking with nissan and infiniti. They said just reset code. Well I did the obd2 reset didn't work I did the pedal reset didn't work and I did the battery reset didn't work. Come to find out the ECM has 2 fuses one under hood in the battery compartment and one in driver side fuse box. PULL THEM BOTH FOR 10min and then codes are gone. (Remember the o2 was replaced) needless to say my cars power is back drove over 100mi and no codes. The ECM must be fully reset to clear this code. It worked gas mpg is back power and performance is back and I am finally code free after a few months. Hope this helps everyone else with this problem."

As for my results. It worked for the most part. What I mean by that is my two codes (P1273 & P1284) would only show up during city driving not on the highway. I'll be specific so bare with me on this reply length. After doing what the above person did, I hopped on the freeway for work which is 49ish miles all over 60mph. Once I got to work I no SES light! So i pulled out my obd2 reader and checked. I only have 1 pending code for a P1283 (before it was p1284) which is a step in the right direction. (Backstory) Just recently I replaced the passenger side post Cat O2 (passenger side o2 are p128X, driver side O2s are p127X) sensor because the last person who had the car put crap test pipes which rusted out and caused me to loose that sensor while driving...literally, it flew right off and i saw it tumble away in the rear view mirror. Now I've got Invidia HFC's. I digress but I know for a fact its not the sensors. So i clear the code and let it sit while i go to work.

After work i put a few more city miles through it on the way to his place. I arive there read the pending code for p1283 again. This time do the procedure again. In addition to pullling ECU fuses I also pulled the 15A fuse for the O2 sensors (located under the steering column) then do the Ecu reset procedure again. After that I drive about 10 city mi to the highway and head home. Normally the original msgs would have come on in about 5mi but nothing. I haven't checked for the pending code and don't plan to unless I get the SES light again. I hope this kinda helps someone.

shadowoffair

False alarm the SES light is back... This time the a/f mixture codes are switched. Now I have P1274 and P1283. I'm beginning to suspect that i have a bad ECM. The ecu, ecm, & pcm are one module from my research. It would explain why I have intermittent starting issues as well as the mixture codes. I believe I'll be going to the dealer for a diagnostic, reflash or replacement.

shadowoffair

Update: i just got back from the dealer. Had a buddy that worked there so luckily the visit cost me nothing. For now.. what he said basically lined up with a lot of what is already on the net to read about the a/f mix issues. Once you put test pipes or high flow cats on z's the o2 sensors are prone to throw mix codes Simply cuz the oem cats are gone. He told me to use the O2 extenders or ill need an aftermarket ecu flash to make it ignore the condition.


As far as my random no starts go its apparently my key. Its not the oem key so ill be getting a oem new key and fob Soon they didn't have one in stock so i have to wait a bit.

jhc

Look up ''O2 no fouler fix''. Less than $10.

shadowoffair

Please link it if you would be so kind. But i believe the one are referring to is the o2 sensor delete but im not sure if thats what you are talking about.

I already have 1 non fouler so i will just need 1 more. The test pipes i had had them but the other side got lost when i had to replace a sensor ill hit the auto parts store up shortly

jhc

Shadow, this should fix you up. NOTE, this is for Audi, so sizes are not appropriate.

Decent write-up, you'll get the general idea to back the sensors out of stream. Good luck,and post up results!

http://www.audizine.com/forum/showth...-High-Flow-Cat

shadowoffair

Update: I have the two drilled out spark plug non foulers needed to attempt this fix I just haven't installed them yet. In the mean time I changed my tranny fluid and the diff fluid and boy what a difference!! It had a little bit of grinding in 5th and 6th so I hoping that fresh lube will fix that. I used Amsoil syn for the tranny and Mobile1 for the diff. I took it for a drive around the block and the gears felt sooo smooth, like a new car. There is a super simple writeup here on the forum so look it up if you wanna do it.

I'm still waiting on the dealership to alert me for the arrival of my new key a so I still have random no starting issues.

Also. I replaced my driver side window motor because it would role down on me half way after using the auto up function. I did reset it once but it started doing it again like a day later, so I just replaced the sucker. Hopefully this motor will work better even though the sticker said made in china.

shadowoffair

update: i have used two non foulers as O2 spacers and still no fix. I will be adding a 3rd to each side tomorrow.

I am also upgrading my front rotors and pads because the brake squealing is unbearable now.

I'm pretty adamant on getting rid of this check engine light so in the mean time could someone please point me towards a popular tuning company in TN or "bolt on" user friendly interface? I know I don't have enough mods to validate a tune but me and this SES light cannot coexist. Someone is leaving.

jhc

Question- how did you reset cel after changes, disconnect black battery cable or with a scanner? If you don't reset it could several days to go away...

shadowoffair

Used an obd2 reader and i did the ecu reset. It didn't fix it. I added a 3rd non fouler to each side and it delayed the ses light for quite a few miles but it ultimately showed up again the exact same codes. I'll be attempting to stack a 4th one onto each side tomorrow/today.

jhc

Refresh my memory pls, how many miles on these O2 sensors?

shadowoffair

Are you saying that it could take a few days for the spacers to take effect?

On the passenger side after cat
sensor maybe 300mi the rest are probably from the factory so 101k mi. After swapping one and not getting a good fix on that one side i don't think its the sensors. But i could be wrong. I just didn't want to throw another 300+ at it for nothing. I guess im just avoiding spending the money if i need to but idk if it really does.

A friend and Nissan tech said put the foulers on it after i paid him a visit at the dealer where he confirmed everything i read and that everything is ok really. I know he did a good job looking it at it because i could hear him revving my engine as it was hooked up to the test machine. It gave me the chills lol. He did a factory fuel relearn on it and it worked for almost the entire day..

Idk if i stated this before but before when all sensors were original the passenger side was throwing p1284 (rich) and after swapping the one sensor plus multiple ecu resets the code switched 1283 (lean). It also inversely affected the driver side switching it from lean to rich.

shadowoffair

Update: this will probably be a while before i update this again. But iv stacked 3 nonfoulers on each o2 sensor so it takes about 25+ miles for the ses light to return. I haven't noticed any performance issues other than fuel economy. for me i only get about 1-2 miles less highway (according to the on board milage meter). I will add a fourth at some point soon. After my plenum spicer it will get tuned to delet the code.

I got an new key and fob so my random no start issues are solved

After my tranny oil & diff oil change it seems to shift smoother and smoother over time. A quality clutch kit seems to be my next major item after tires. But still ill look into a new transmission or overhaul. Its summer so i don't expect the smoothness to last come cooler months.

Driver window motor is still great. If you ever have any issues just replace the damn thing.

Only immediate things left are 2 front tires, tranny eventually as stated above and a fresh paint job.

Cheers all

Kernalmantis

Hey everyone, new here and having same issues as OP. Were you able to make any headway with the p1273 and p1284 codes? Did you end up getting the tune?

shadowoffair

Nope. Codes still exist even after a full exhaust swap minus the headers. I've just gotten used to the SES light. tune seems like the best option.

Another random update:
The new key and fob did not fix the random no starts. Apparently some quick research is now pointing to the NATS computer which is part of the ignition system and changing that would cost $$$$ so im living with it for now. Other than that car is great even with heafty oil consumption...looks like a catch can is in the works now too.

I drive the mess outta this car and it's great

cheers all