bhairya

Hello folks,

It's been a long time but, as they say, necessity is the mother of invention or something like that. I'm having some trouble with my beloved 2003 Maxima SE manual. It's got about 178k miles on it and it's still my daily driver. For the last couple of days, the SES light has been flashing and I'm noticing sluggishness and some vibration. The SES has been on and off for several months now but for the last few it's stayed on. The flashing is new. I just got an oil change from the dealer (can't beat the $9.99 coupon) and he gave me the OBD codes. He also gave me a $280 estimate to do an "in-depth diagnostic" into the codes, a $1260 estimate to change all 6 plugs and coils (I just asked for it, not that they said that's the problem). Plugs (and one or more coils, I can't recall, maybe rear ones) were replaced at about 100k miles. My right side mirror is also broken off (son hit it with a basketball) so I duct taped it for now. Estimate to replace housing while keeping the painted mirror enclosure: $360!

I'm not really one to work on my car much. However, based on the fact that I'd like to keep it and the potential cost have these issues repaired/fixed will probably be prohibitive, I guess I've gotten some motivation to try to tackle some of this myself. Here are the codes:

P0420
P1800
P0300
P0328

I'm not quite sure where to begin or how to go about trying to figure this out. I do know that one code often triggers another, that it can be difficult to diagnose/troubleshoot and you have to fix/replace one thing and check again. I'm requesting the collective knowledge of this very helpful group to help me with that. Thanks in advance!

Upperhand

:insert/gameover emoji/?n, :insert/SES light smack in the face repeatedly emoji/?n, :insert/ghosty ride off clif emoji/?n

Upperhand

Jokes aside you have your work cut out for you. Don't ignore SES lights! P0300 is random misfire that's why your SES is flashing. It kindly flashes to warn you that continuing to drive may cause damage to your catalyst(s), which may or may not be why 420 is showing up(catalyst function in question). Code 1800 has something to do with the VIAS valve, and code 328 has to do with your knock sensor which sometimes is a false code. Solving P0300 should be right next to P0420 at the top of your list of prioritys. Look into P0420 on the forum and see if it's something you can tackle(replace/gut and sim).

Les7311

If you not a man with some tools, then find some friends who have. The codes are DIY fixes. But if you not willing to do it or your friends then you back at square one.

Type into google: what is P0XXX code on a 200x maxima. See what pulls up. Do the same in YouTube.

Also, eBay is better than stealership or local store cost. Example: spark plugs at dealer is about $12.....you could find on eBay for about half and no tax.

If you was close by I would tell you to bring car over and let's do some surgery. Good luck and keep us posted.

Upperhand

bhairya

Thanks for the humor, Upperhand. I do realize I have some work cut out for sure! I've spent several hours reading threads on here to make a list of possible ways to attack this. I want to know where to start. My fear is just the uncertainty of the codes that are thrown ie. reasons behind them. I found this out with my mechanic whom I've been going to for over a decade. In the past, he read codes which showed some sensor faults, changed the sensors, and the codes were still there. After being out about $300, he then asked me to go to the dealer because he didn't want me to spend more money needlessly. Seriously!

bhairya

Thanks for the offer. I've looked at spark plugs online. I also looked at coils. OEM are $100 a piece! I read somewhere that you should use OEM coils only? I have had some changed (I think) when I did the plugs at 100k. I've got basic tools but not specifically auto ones. I'd need to get the spark plug wrench/socket at least. Don't know if I need torque wrench, too. What do you recommend in a basic auto repair tool kit? Thanks.

Upperhand

Here's the factory service manual. Select your year, select the "EC" section and you can look up all your codes. They're in the index.


http://www.boredmder.com/FSMs/Nissan/Maxima/

Les7311

I changed the spark plugs on my 05 two times. They were relatively simple ... about a 7 out of 10 with 10 being the worse. Then I did my '11. 2 weeks ago and I didn't even look at a manual. This was about a 5 out of 10.
you can pick up an inexpensive socket set that has a spark plug socket included for under $20. Go to harbor freight. You will need a socket extension to get deep into the well.

If not mistaken, you may have to remove the plenum to get to the other 3 plugs and that where your technical skills comes into play. Watch the YouTube video and use that as your guide. You will be happy if you take on the project and complete it. It should take you about 3 hours .....taking your time. Label what you remove. Don't be afraid to Force move something to get to another part. It's all a part of mechanics.

I don't know the 03 engine compartment but I don't think its way far different than the 05.

If you do plan to take in the project, we can talk via phone... I can do some homework also. Just be prepared to do a tele-mechanical surgery many miles away.

If you do find the YouTube video for your car, post it on this post and we can gauge it usefulness towards your surgery.

Willing to go the distance to pm my cellphone

Les7311

Also, to check if the coil is bad:

Start car, with hood open, remove the coil and listen if engine become sluggish at idle. Reconnect and runs normal. The coil that doesn't respond when removed is the bad coil or spark plug. ..... another YouTube video out there

kauaiwyatt

iTrader: (5)

Don't waste big $ on new coilpacks (although i put new ones in the rear under the plenum). Just buy used OEM ones from a junkyard or eBay. Same with the mirror.

VR6JH

First of all, dont drive the car with a flashing SES light. Thats bad. Like really bad. Could be catastrophic. Stop. Please

Dont waste your time with coils. If coils are bad, you will usually see a specific cylinder misfire. I've never had a coil lead to a random cylinder misfire. Not saying its not possible, just sure as heck wouldnt start there.

Your 0420 is either a bad cat, or bad 02 sensor. Will need to be fixed, but car should run mostly ok. Put that on the back burner for now.

The 1800 code is for the VAIS solenoid. Basically changes intake runner length under different RPM/load conditions. I would check vacuum lines running to it. Possibly they are off/corroded/broken. This would cause the car to run/idle poorly. Needs to be fixed

0328 is a knock sensor code. This is likely related to the random misfire. Its possible you have a bad tank of gas, or something. Possibly knock sensor is bad.

You need to 1) Address the VAIS solenoid. 2)Change the spark plugs, basic tune-up 3) Either while your in there, just replace the knock sensor, or try throwing in some fuel treatment and run the crap out of it. 4)After all that, once those codes are cleared up, then you can address the cat efficiency code.

You can go to the junkyard and get a new mirror for like $20. I replaced the front bumper, door, fender for like $120 on one of my maxima's.

bhairya

I've been watching some YouTube videos on plugs/coil replacement and how to diagnose and your advice is what it says to do. I'm making a list of things I need to check/do while I have stuff open eg. vacuum leaks, hoses, intake gasket, etc. Reading on possible causes of misfires and this is one of them especially when you have P0300 instead of a specific cylinder code. Thanks!

bhairya

Yea, I'm not driving it. The blinking light only started a couple of days ago and it's blinking every time. It happened once before but that was a long time ago.

This is a good list to start. So I'm definitely changing the plugs. About the random misfire code P0300, I read somewhere that it might be a good idea to clear the codes, start/drive the car a bit and as soon as the SES light comes on, check the code again for a specific cylinder code?

I put a bottle of chevron fuel system cleaner into an empty tank and filled it up with about 2/3rds premium gas so that shouldn't be an issue.

VR6JH

I think doing plugs is a good start. While your in there, you'll have access to lots of vacuum hose to check their condition. You'll have the intake off so you can inspect the vais, and with the intake off you'll have easy access to the knock sensor. I'll what they cost, but I'd just go ahead and replace it. Cheap insurance.

You do run the risk of discovering a bad coil on the rear bank after you get it back together, which would require removing the manifold again, but I really doubt they are an issue.

bhairya

I can test the front coils as you have described. This may be a silly question, but how do you test the back coils? To get to them, you have to remove a whole bunch of connectors, hoses, etc. How can the engine be running while you have all that off?

DennisMik

iTrader: (2)

The flashing SES light means that a coil mis-fire is happening at that instant. It is not a catastrophic thing. Yes, the engine is not running properly but it will not destroy anything. The VQ engine is a good design, it will start and run on 3 cylinders, very poorly to say the least, but it won't hurt anything.

VR6JH

You don't. Really no way to access the rear coils with the intake on. There are guys plenty more knowledgeable about these cars then me on this site, so I don't want to steer you wrong, but I've NEVER had a case where a random misfire was related to a bad coil or a case where a bad coil didn't throw a specific cylinder code. I'm not saying that isn't your problem, but I really think you're wasting your time there. Fix your known issues. If you still have problems, then you can move to the coils.

bhairya

Ok so I got the bluetooth OBD reader I'd ordered. Installed torque lite on my tablet and tested it out. I checked the codes and the only ones (pending) were P0300 and P1800. I cleared them and the SES light went off. BTW, what's the difference between logged faults and pending faults? This is what the torque app shows.

I then drove the car around the block and took it on the freeway, too. The car drove fine. The SES light did not come back on. Idle RPM, according to torque, was between 630 and 750. Once in a while, it does dip and little bit and I get a slight shudder but that's not new.

I did get an oil change from the dealer yesterday and, when I was driving back home, I was still getting the flashing SES and slight sluggishness. No more. I had only 2 quarts, yes 2 quarts, of oil when they drained it! This is another issue I've had with my Maxima. I cannot accurately figure out when the oil level is low. The dipstick sucks! I've asked the techs at the dealership service to show me and they saw what I was saying. The service manual says to run engine, turn it off and check level after about 15 minutes or so. Doesn't really work because there's oil all over the stick. I've checked it cold and that's what the tech told me to do. I told him that's opposite of what the manual says.

I don't know if the low oil level is part of the reason but the SES light has been on for quite a long time. I've just had it cleared a few times by my mechanic. I'm going to wait till the SES light comes back on (if it does) and then check the code/s immediately. Start with a clean slate, I guess. The plugs are on order so I'm going to change those regardless.

Thanks for some great advice and info on my thread. I'll update this as things move along but I'm encouraged by the support I've gotten on here.

VR6JH

A fault has to "mature" from pending to active. I'm really not sure, but if a fault occurs more than a certain number of time during a cycle, then it becomes active. Maybe someone can explain that better than me.

I always check oil cold. Usually in the morning after its sat all night. Otherwise I can never check it accurately. It may not be "exact" but with as much oil as the 5.5 gens burn, it'll be fine.

Ate you doing the plugs yourself? Comfortable removing the intake manifold? Not a hard process. You'll have to do a throttle body relearn. Also a good time to clean oil sludge from the TB.

REALLY check all the vacuum lines. They're so cheap and can cause weird issues if cracked/leaking. With that VAIS code just makes me wonder. I could be wrong though too.

Les7311

"Soft Code". Shows up intermittently then goes away. There is a problem but you can get around for a minute. Just a matter of time before it turns to a hard code. Then again it could correct itself.

"Hard Code". Every time you start the car, the code is there and will not go away until fixed.

bhairya

I'm making a list of what else I could do to make the car run better. About cleaning the TB, I read a few threads here and on other websites about how much trouble people have had when they tried cleaning it. There are multiple methods: removing the TB, not removing it, flooring the pedal, turning ignition on to have the butterfly open, etc, etc. Most people have recommended NOT touching the TB at all. Many had to replace the TB, go to the dealer to reprogram ECU, idle relearn procedures not working, messing with injectors, and all sorts of problems. I found it a bit weird that simply detaching and cleaning it would cause so much trouble but apparently it does on the 2003 and up Maxima. Anyone of you clean the TB on yours? Success/failure? Any other recommendations for maintenance while I'm doing the plugs? Cleaning the MAF, etc?

Les7311

Never manually open the "butterfly" on the throttle body!!! You will throw off the ecu functionality.

If you have to clean it, do remove the case attached to it and with the car running "spray" the butterfly while someone is depressing the pedal. This will spit large amount of white fumes through the tailpipe.

bhairya

You sure I should do it with the car running? One of the instructions that seemed to work for people was to turn the ignition to ON, put something to hold down the pedal so the throttle is open, and then clean it? There's a whole long thread about this and my head hurt after going through the entire thing.

nestorlugo

iTrader: (11)

This is 100% true! Ask me how I know

Les7311

Many ways to skin a cat.

No change above. As I am removing the tube, and with the engine running and someone sitting in the driver seat,.....pssssttt. Pssssssttttt ppssssssstttttt. Driver quickly feathering the pedal

This is with a small opening of the tube so I can spray (pssssstt. Pssssttt) the butterfly quickly.

bhairya

Well, the codes are back. Was driving on the freeway and the ses light starting flashing. Pulled over to check codes: p0300, this time p0306, p1800, p0420. Took it to my mechanic who was close. He couldn't figure them out and said p1800 could be "serious." Told me to go to Autozone and have them check and see about the part which I'm assuming is the solenoid.

I also saw this tube and would like to know what it's for and why it's not connected from one end. Can someone tell me what this is?

Child_uv_KoRn

iTrader: (7)

That's just breather tube for tranny.

Knock sensor is bad, apparently.
O2 sensor or cat (likely) is bad. Gut them or headers before car goes on CL for 500 bucks.
VIAS solenoid is bad.
And you have multiple misfires.

What coils and plugs were used (important)?
Could be vac leak like torn intake boot.
​​

bhairya

Ngk iridium if I recall. Coils were aftermarket. I don't understand what you mean by "gut them or headers..." can you explain?

I drove back home with AC off and no issues. I revved the engine to 3000 rpm and higher and looked at the vias solenoid. The piece that is supposed to move did not move but I could move it by hand so it's not stuck. Does that confirm a bad solenoid or is there something else to check? Autozone has it for about $131 but I'm seeing it for like $15 to $90 on amazon and eBay so I don't understand why the big difference. Can someone please confirm the part is 14955-8J10A and that's what I need to replace?

bhairya

The mechanic told me that the p1800 could be causing the misfires so address that first. The guy at autozone agreed. However, the ses light was flashing even while I was parked with engine running. Then it went away and didn't come back on at all. I drove without AC on the whole way. Not sure if that's related.

Child_uv_KoRn

iTrader: (7)

VIAS affects nothing. Aftermarket coils can cause misfires. Being intermittent is odd.

I'd swap with known good coils and pick them and the solenoid up at the junkyard if you don't know anyone.

Maybe if you live near another org member they can swap ya coils.

How long were you on that oil? Precats are already at work it sounds like.

bhairya

I'll change the VIAS solenoid. I change oil about every 3k miles now. What makes you say that? I'm trying to learn whatever I can. What's the function of precats, cats, etc?

Child_uv_KoRn

iTrader: (7)

Yeah, that kind of consumption is indicative of the precats eating your cylinder walls/rings. It will get worse and kill compression. Google nissan precat failure.
Cats are for useless emission standards.

bhairya

After reading many threads here and on different forums about pre-cats, etc, I'm beginning to think this might be the end for my Maxima and it's depressing me. I really like this car and, the fact that Nissan doesn't make manuals anymore, makes me want to keep this car for as long as I practically can. I'm starting to wonder if there's even any point to changing plugs, maybe coils, etc, if the pre-cats are eating away at the engine?

I live in TX so can the pre-cats be gutted? I read somewhere that in places with emissions testing, mechanics don't do it? My Max has been knocking for a few years now and nobody, even the dealer, could tell me why other than saying it's an old car bla bla. I read a post from someone here about gutting pre-cats which greatly reduced the knocking. I have this at lower RPMs when I ease off the gas.

But then I think maybe I should try to prolong the life as much as possible. First order of business, get rid of the P0300? I don't know.

DennisMik

iTrader: (2)

Getting the P0306 is a help. It is one if the coils that is failing. There is at least one more. Maybe after you replace # 6, you will get another number.

Pre-cats were added to cars because the main cat doesn't heat up fast enough to do its job when you first start the car. Pre-cats are only needed for maybe a minute and then the main cat is doing its job. Many people have either gutted the pre-cats (a real pita) or they have replaced the y-pipe with one that didn't have them (me).

Asking a licensed mechanic to defeat a pollution device is illegal and the mechanic could loose their license.

However, with the P03xx codes happening, the car is pumping raw gas into the cats. Fix the P03xx codes and maybe the P0420/30 codes will go away, maybe.

Child_uv_KoRn

iTrader: (7)

Only 2000 fed spec has both cats in Y. 3.5s have both in the manifolds. They have to go. If he was over 2 QTS low in 3k mi....his engine is half shot already.

bhairya

Ok, so what options, if any?

Child_uv_KoRn

iTrader: (7)

Same as before. Gut or headers.

bhairya

How do I get the pre-cats gutted if I can't get a mechanic to do it? I don't think I can take something like that on myself. What are headers and what do they do? Thanks.

bhairya

Since I started this thread, the only code remaining in the 0300. Went to plan B and got another car because the DIY wasn't quite happening. Just found a mobile mechanic who's been helping me. Here's what he's done so far:

- Replaced vias solenoid & vacuum lines, no more P1800
- Replaced plugs, all were burnt blackish
- Ran seafoam
- Cleaned MAF and sprayed cleaner into throttle body
- Knock sensor wire was "eaten" away and connector, too. He said there was a rat's nest! He soldered a new connector and fixed the 0320.
- Checked all vacuum lines & couldn't find any leaks

The 0300 remains and SES light flashes soon after starting/driving a bit. There's also this strange burning smell I haven't smelled before.

When he first started he ran seafoam and the car ran fine for 3 days. Almost got it to pass inspection had it not been for some of the emission readings not ready. The codes returned shortly after that.

I haven't really driven the car for several months since all this began other than driving it around the street or parking on and off the road till I found this mechanic. He's going to do some research and talk to some mechanic buddies because he's at a loss about the 0300. Any ideas guys?