Bobo

I have had an issue for about the last 6 weeks on my 95SE that I have owned since day 1. It has 180,700 kms (112,300 miles on it).

The day after I bought gas at Costco the CEL came on when I started the car. If I warm it up after driving for awhile, turn it off and restart it, most times the light is not there.

Sometimes I start it and there is no light at all. The light never comes on when I am driving the car.

I do not have an OBD II scanner. I am just going to take it into a shop and get them to read the codes.

The shops I have dealt with typically want to scan for codes even if you tell them what the code is.

I filled it up recently after being quite emply, still the CEL problem. I thought I might have got bad gas at Costco, not the case.

Anyway, I had a fair amount of highway driving on the tank full and got about 25% less MPG than I would have expected.

I believe I also need a knock sensor but the car seems to run just fine and I don't think a knock sensor affects fuel economy that much.

I replaced a fuel injector last August.

Could this conceivably be an EGR valve issue? It has never been checked. I have a Haynes manual and it says how to check it but I am too mechanically inept to even locate it.

I don't believe it is a MAF issue because the car runs fine. It might hesitate a bit when stepping on it at lower RPMs but that could be the KS retarding the timng.

Any ideas before I get the codes read?

The shop can't check codes if I bring the car in with the CEL off.and it is hit or miss.

JvG

Code readers and scanner's are quite inexpensive compared to having your codes read at a shop.

You really should have one of your own.

I use the BAFX scanner which works with my phone.
It costs about 20 dollars on amazon.

The scanners also check for pending codes.
So the cel does not need to be on when you check.



The knock sensor code rides along with many other codes. It's only significant if it shows by its self.

Bobo

The knock sensor code does not trigger a Check Engine Light, nor does a bad KS affect fuel economy significantly, correct?

JvG

The knock sensor generally does not have to be replaced unless it is the only code present.

A defective knock sensor will limit timing advance.

A functioning knock sensor will allow full timing advance if the recommended premium gas is used.
The car will have more power and better mileage on premium. I get up to 32-35 mpg at freeway speeds with my 5 speed.

Bobo

I live in British Columbia and fill up at Chevron with an equal $ amount of 87 and 94 which gives me 90.2 octane at 89 prices.

I used to get it for about $2 cheaper than 89 that way until they messed around with the spreads between the octanes.

My fill on the weekend got me just under 25 mpg to an Imperial gallon. There was a lot of highway driving involved and I expected at least 32 mpg.

I have gotten 37/38 on 500 mille + round trips at freeway speeds with climbs from sea level to a few thousand feet in elevation and back, carrying passengers and luggage.

You would cringe at the price of gas where I live on Vancouver Island, Cdn$1.599/litre for 87 and higher in Vancouver because of transit levies.

JvG

I've noticed that malfunctioning oxygen sensors can cause fuel mileage to drop a lot. The car will seem to run just like normal.

Keep in mind that NTK sensors are made by NGK.
Our cars like them. I'd shop on line. I don't know about Canadian parts sources or import duties.

Zerodrag

iTrader: (1)

https://en.wikibooks.org/wiki/Automo...a_screw_driver

PH98I30

Read your code and let us know what it is.....

Bobo

I replaced an oxygen sensor years ago. I believe the 95 has 2 of them, correct

I didn't notice any issues then other than the CEL but needed to replace it right away to pass Air Care
when I lived in Vancouver or I couldn't renew my car insurance..

I have an Excel file going back to 2002 with all my maintenance on it. Can't see the expense there.

It must have been replaced prior to March 2002.

JvG

There are generally two oxygen sensors. Two up steam, located in each exhaust manifold, and one after the cat. We are talking about the ones in the exhaust manifold. These are referred to as
upstream oxy sensors.

Get your self a scanner. Then tell us what you find.

Bobo

I am looking at my Haynes manual and it says there are two upstream oxygen sensors (one for each cylinder bank) and one downstream oxygen sensor.

The upstream oxygen sensors control the engine air/fuel ratio and the downstream has no effect on air/fuel ratio. Perhaps the downstream sensor affects emissions, not sure about

that but when I replaced a sensor I was told that I needed to or I would fail emissions so perhaps it was the downstream sensor that was replaced.

I am not going to try and read the codes with a screwdriver because I don't want to break anything here and even if I told a shop what the problem
was they would just charge me for a diagnosis and read the codes anyway.

Even the stealership did that years ago when I told them I had an evap solenoid issue and gave them the code # after I shop I went to read the code for free.

JvG

Yes, the upstream sensors help control the air/fuel mixture. The downstream sensor monitors the health of the cat.

The shop probably replaced one of the upstream ones. So it's possibly or probably the other upstream one.

But we are just guessing till we know what the code is.

Get the code read somehow, or buy the scanner I reccomended, or another one if you want.

A scanner belongs in your tool box just like a torque wrench does. Both are vital if you want to work on the car much.

I'd want to own a scanner even if I had a mechanic work on the car. It allows the car owner know what's going on.

Bobo

I am a 67-year old retired accountant who is mechanically inept and has no tools to speak of.

I ride my road bicycles about twice as many miles a year as I drive the Maxima and it is my only car.

It has been driven on average about 3,000 miles per year for the past 6 years.

Where I live I can walk to most of the stores in 5 minutes and the car sometimes isn't started up for

a week.

Sorry, I digress.

I am going on a road trip in about 6 weeks and just want to head out with peace of mind.

Not sure why the oxygen sensor failed when it did. The car would have had less than 43,000 miles on it. Not sure how much less.

JvG

I'm a 65 yo semi retired former investment guy.

Cars have been a fun and neccesary hobby since high school.

Thanks for letting us know your circumstances.

Seems like your car could sever you for many years to come.

Bobo

It has been very good to me. I still have the original alternator.

I only replaced the front brakes abut 2.5 years ago. I didn't use them much. 5-speed manual, I would down shift or coast up to a light.

Differential carrier bearing issue before. Fixed. Replaced clutch kit at same time with 50% left on it.

Starter, Coolant temperature sensor, Evap control solenoid, 2 fuel injectors, no coils, a couple of batteries, hood shocks/struts, muffler, tires twice. That's about it.

Car has a Budget stainless steel y-pipe, FSTB, K& N panel filter, rest is stock 4x4 look with original sawblades

KP11520

Sounds like you have no intention of replacing this Maxima.

$20 is a breadcrumb to be able to talk intelligently with facts here and to Mechanics, if you go that route!

NO BRAINER!

JvG gave you the absolute best advice when he suggested that BAFX Bluetooth reader. Although your first post sounded like an O2 sensor, nothing like knowing for sure before buying and also buying the right one of the three.

There's a guy on eBay in Cali that sells the NTK for our 4th Gens sparkautoparts and I did mine and they averaged a little over $30 each shipped.

Even an Accountant that can change the seat height on his bicycle can replace these. LOL I can and use that money on illegal activities!!!! (kidding)

JvG

I can and do use some of my labor savings to purchase a certain herb which is fully legal on the west coast of the USA and now all of Canada.
New York might take a while. Once it does, the east coast will follow.

I fully agree with purchasing the 20 dollar scanner as a means of getting helpful advice.

Bobo

I guess I will bite the bullet.

I buy my road bikes and get profesionally fitted and never adjust the seat height thereafter.

I can fill up the gas tank, check the oil and add air to the tires, that is about it.

Bobo

Those days are behind me and them some. I have seen The Doors and Led Zeppelin both twice. That is how old I am.

PH98I30

I saw the Doors and Led Zeppelin and Canned Heat and a bunch of others too. You can get a basic OBD2 scanner at Walmart for about $15. Just plug it into the OBD port and read your codes. It's that easy. That way you don't have to guess and waste money.

Bobo

So I have 2 codes.

P1320 Primary Ignition Signal Fault
P0325 Knock Sensor

I knew about the knock sensor, but the P1320 is new.

Not getting a code for a cylinder misfire or a cam or crank position sensor.

The individual coil packs haven't been tested.

The power supply was checked and is in spec.

Stopped the shop there.

They want to check ground circuit and each ignition coil last. Not done yet.

KP11520

So what are you asking?

Bobo

Just responding to PH91830 who said to read the code and post it.

I am under the impression that if I have a P1320 code I should also get a cylinder misfire code.
I have also read that conceivably it cold be an issue with a cam position sensor of crank position sensor but would have thought a code separate from P1320 would come up.

I will check the coils, but it could be something else electrical in nature, such as an ignition coil harness connector or ECM harness connector.

Failing that if the ignition coils are OK, it could be the ECM pin terminals.

All of this is according to what a shop printed out.

I stopped the after they confirmed the power supply was ok.

They wanted me to leave the car with them. This was 3:30 in the afternoon and I didn't want to leave the car overnight.

and wasn't sure if I could have gotten it back until Monday.

I phoned the stealership yesterday and they questioned whether it was a coil because they said I should have gotten a cylinder misfire code as well which I didn't.

KP11520

For some reason, coil packs don't always kick out a code as they are declining. Neither do failing fuel injectors.

But that video above shows the easiest way to confirm by symptoms on finding if a coil pack(s) is checking out. DO IT!

Even an Accountant can do it.

These cars are old enough that if we don't learn to diagnose and fix yourself when capable, they will $50 and $100 you to death at the mechanics. Nickle and Diming is a long gone. More mechanics these days, throw parts and labor at problems, rather than diagnose properly and nail it the first time.

Or pay them and soon enough it could be enough to buy a much newer used car with less aggravation for the same net amount.

Bobo

Thanks. Will do.

In the case of fuel injectors I have replaced 2 and both times I got a misfire code.

KP11520

Installation of injectors is delicate as the O-Rings can be displaced when installing unless pre lubed and installed gingerly. Quality can also be a factor for outright failure out of the box. Many Chinese made cheapies have a much higher failure rate. I use a rebuilder that tests and flow matched all six so the cylinders aren't conflicting. When injectors get replaced, they are seated in rubber grommets. They need to be replaced too as do the cushions on top under the cap. Most mechanics ignore this.

Bobo

So if I hear you properly you are saying that the rubber grommets do not come with the fuel injectors. If so, mine were never replaced AFAIK.

Bobo

I will also check the spark plugs to see if any are fouled. I replaced the OEM ones at 108,000 kms with NGK laser platinum OEM plugs. They have less than 73,000 kms on them (45,000 miles).

KP11520

How did spark plugs get into what to do next? DO THE RUNNING COIL PACK CHECK as shown in the above video.

Why do people come here and resist the diagnosis logic path and change the subject?

Are you saying YOU will check the plugs or the mechanic? Based on what you said about your bicycle seat, I am suspect. If you can check the plugs, the coil pack check is between you and the plugs.

If we're here to tell you what to tell the mechanic, That ain't how it works. For me anyway. JvG can help. He has more patience.

Bobo

Obviously the coil packs are checked first. My car is probably in the bottom decile of 4th Gen mileage on it on the planet.

I am simply trying to draw on the experience of peeps who have 2 or 3 times the mileage on their vehicle than I do and have encountered the P1320 code before.

Whether I do the work, a friend does the work or a mechanic does it is irrelevant as long as I some sense as what I want to check and what sequence.

The sequence they were proposing at Canadian Tire came from their computer system and must have been from the FSM.

Another guy at the stealership told me today to check the coil packs first. If ok check the plugs before the other stuff the printout said.

JvG

I agree with all of what KP said.

Vom meters are inexpensive and easy to find.

One can test for ohm resistance while the coils are still on the car.

It's best to remove the coils for inspection. It's possible that you might find ones covered in oil.
The oil would cause misfires. The cause would be a leaking valve cover.

Since the existing plugs have 40,000 miles on them, you might as well replace them with new NGK plugs if the coils are out anyway. You could keep them in order and take a closeup of the electrodes so that we can tell how your engine is running.

Regarding injectors. Our cars are at the age when these are leaking quite often. Since removing the intake manifold is a time consuming pita, it makes sense to replace all three of them if the intake manifold is off for any reason.

Injectors can be rebuilt and flow tested.
I imagine that there are companies in British Columbia which do this.

I accept that our cars are old and that parts are failing. That's why I proactively replace parts while I'm in there anyway. Sure, that costs more money initally. The payoff is having a reliable car which I dont need to work on very often

It's also true that there comes a point where the car breaks down so much that taking the car to a mechanic for everything becomes prohibitably expensive. That's why people make car payments.

It's not to late to develop a new hobby. Like delving into car repairs. It gets easier as one builds experience.

Bobo

So my problem is with the #6 ignition coil.

From what I can see there is a lot of discussion about Hanshin and Mitsubishi. My 1995 is an 08/94 build.
I can get a Hanshin.

There is also Denso but I haven's seen any discussion about them.

The stealership doesn't have any coils and if they did are a lot more expensive and may just be a Hanshin or Mitsubishi dependent on the car build date, with their stamp on it

Any recommdation on which to use?

I was going to go with Hanshin.

Anyone have any experience with Hitachi?

Thanks

JvG

Supposedly both work just as well.

Good luck.

Bobo

Problem fixed. Went with Hanshin coil. Car runs like new..