Hello. I'm new here. About a year ago I stopped at a really off brand gas station. I normally get Chevron Premium, but this was the only station available. I didn't think it would be much difference until I started the next morning. It sounded rough like it wanted to turn off. I though maybe it was the gas. So I refilled with the usual chevron but it didn't make much of a difference. I Ignored it at first because the problem always went away with me restarting the car. For the last year I had to restart it so it would run normal about 6 times which was only when I was getting low on gas.
So now The BIG Problem. Last week when merging onto the freeway my CEL began flashing. When I got off I tried turning off my car to stop the rough idle, still no difference. When I Accelerate above 40 MPH it begins to flash again, though it runs smoother at higher speeds. I assume it may be the fuel injectors? I refuse to take it into a local shop since they all require 100$ to simply diagnose what it is. With my scan tool I get P0303. I am thinking it may be the fuel injectors? Has anyone experienced anything similar to this?
Also, are the fuel injectors hard to change? The local mechanics want a diagnostic fee along with 900 if it is indeed the injectors.
This is my first Infiniti/Nissan. Prior to this I owned an 02 olds aurora 4.0. northstar I did all the maintenance myself which was easy to me. But I don't know about nissans... any suggestions will help.
Thanks.

 

A flashing CEL indicates a misfire, and you should pull over if you don't need to be anywhere. If you absolutely need to drive the car, go easy on it, like real easy. If there's fuel being dumped into the precat, that's asking for trouble.

It is very common for the coil packs to go bad on these cars, so step 1 would be to replace ALL (if one died, another is soon to go) of them with Hitachi branded ones. Do not cheap out on coil packs or you'll be replacing them again.

 

Sure it could be bad gas and a plugged fuel injector. But thats not my first choice. I would suspect a bad coil in cyl 3. Simple replacement. Check the plugs while you're at it. Also, I would try a fuel system cleaner with polyetheramine (PEA). Techron Techron Concentrate Plus is great, or my new favorite Gumout Multi-System Tune-Up which is part Seafoam (IPA for water dispersal), and part Techron with PEA. Love the stuff, using it on every engine I own large and small. Drop a can or 2 in a tankful and see what happens. You can't OD

https://www.walmart.com/ip/Gumout-Mu...16-oz/43913005

 

Usually if the misfire gets bad enough the computer will throw a code for a specific cylinder. U should purchase a code scanner they are about $20 now in Walmart. Try to refrain from using low octane gas also. Usually if the light flashes there is another code that follows it. Also keep an eye on the oil check first thing in the morning and whenever spirited driving check after maybe 20-30 mins of turning off engine.

 

That was my first thought, The fuel Injectors. Everytime I got low on fuel it would run rough until I filled up with Premium, then it drove like brand new. In November I purchased a new fuel system cleaner Called Liqui-Mali do to the reviews. I didn't notice a difference. I'm thinking this may have had something to do with it? I have tried other fuel cleaners in the past like The Royal purple, still didn't notice much of a difference. If it is the fuel injectors, It is a 1000 Job. None of the auto shops in my area allow you to bring your own parts. I also dont trust shade tree mechanics. A local mechanic informed me "assuming I didn't know about my own car" That in order to change one, they would have to remove every single injector. Now I have looked at the job, and it seems the hardest part for me would be getting off the intake manifold. Nissan redesigned this purposely to force you to come to them for service. But my first thought is it may be fuel related. Would you think it would be worth only replacing one injector?

 

I have a code scanner which throws P0303 everytime. That is the only code that I get, even after driving it awhile. Also I have always used premium only

 

The funny thing is. The last straw with my Aurora was when the CEL began blinking, but with no rough Idle at all. It drove like a Cadillac floating down the freeway, but I panicked and sold it for 800$. Now this.. This car has been in my family since 53k. I purchased it from a relative when it had 135k, it now has 173k. As far as I know the only maintenance that has been done is regular oil changes. I purchased Lucas Fuel system cleaner for 12$ a week ago. Still no difference

 

Why should there be any difference?
Your car is telling you that cylinder #3 is misfiring. The FSM (pg. EC-315) lists almost a dozen reasons that can trigger p0303, but the most likely cause is either a bad coil, or a fouled spark plug on that cylinder. Given the oil leak/consumption history of our 5.5-Gen cars, I would check the #3 spark plug and the coil before doing anything else.

 

On the bottle it states that it completely eliminates knocking and pinging, so I was expecting for some kind of a difference. Alot of times when my Aurora threw random codes it was because of a dirty fuel system. I added a quart of oil today 5w10 because its getting cold. I noticed during Idle that the sound of the engine kept moving from fast to slow. Also even though it would have random idle during summer that was easy to get rid of, I notice that it started this up as soon as it got cold.

 

are you sure u want to use 5w10 ?? it should be 30 wieght.

 

Lucas are crooks. They peddle snake oil solutions to unsuspecting customers.
The best case scenario Lucas additives do not do anything at all, the worst case they harm the engine. I dunno how bad it can get as I don't use Lucas, STP, or any other snake oils.

You got a Cyl #3 misfire, deal with that. It can be oil leaking onto the plug, it can be a bad coil, it can be a bad injector, or bad wire harness to the injector or to the plug. Pull the plug and inspect it. Get a multimeter and check if the injector and the plug get the power. But stop pouring God knows what God awful donkey **** down the fuel tank!

 

I/we want to help you out. Nothing being discussed here is hard or expensive. What I mentioned as a cleaner had nothing to do with buzzwords or brand. Its the contents, what it does. As others mentioned most is snake oil, very few do anything. Regardless a bottle of something can't cure a mechanical issue. You don't need a mechanic to replace a coil. We can walk you through it. Save the money for something else.

 

Soooo, how do you know it's bad then? There's been several videos comparing Lucas additives, and it does as it states. Obviously everyone is going to have different results and the right conditions must be met, but their Power Steering Stop Leak is a great product.

 

There are lots of videos showing that aliens have landed and zombies are coming.
I don't need to ruin my cars with Lucas/STP crap to know it's crap.

 

Sounds like Lucas inappropriately touched you several years back.
Oh wait, you've never used it so that couldn't have happened.

 

Any tips on removing the Intake manifold? Also would you recommend replacing the cylinder 3 fuel injector as well?

 

The intake is actually pretty easy, there's a couple YouTube videos showing how to do it. Just take your time and it will be easy. People say the trickiest part is removing the two 12mm for the support bracket, but it shouldn't be a problem.

The injectors are normally not a problem, so I would leave it.

 

OK I would first start at the easiest part which is to replace the spark plug and coil on that cylinder. The computer is already telling you what the problem is Po303 there is something going on with cylinder 3 and its most likely the coil is bad, swap or replace and turn off check engine light and drive and see if it comes back on for po303. Ive had same code, and was a bad coil. If you have not yet done so replace the valve cover on the rear bank with one from a 6th gen maxima/ murano/ 2004 and up because eventually it will leak oil into the spark plug tubes.

 

Ok so I was driving today.. Re read the codes. Its now P0300 instead of p0303.. This car is driving me insane

 

Well, have you looked at cylinder #3? Have you replaced the coil/plug?

 

Stop looking for bottle of fix. what brand of coil did you install? if its ebay/chinese and not an oem coil then you will have codes and missfires are alot more likely. take a flash light and peer into the 3 cylinders in the front of the car and see how much carbon has built up. i can see shiny metal on my pistons when i change my plugs. anything black can cause predetonation because the carbon can get so hot that it ignites the gas mixture before the plug can.

 

Wehn driving yesterday I also smelled rotting eggs... Have I destroyed my catalytic converter?

 

the more you drive it with the po300 chances are you will eventually destroy one of the converters because of the unburnt fuel being dumped into it.

 

Thanks. I have come to the conclusion that I'm not putting that thing back on the freeway untill I resolve this issue since I only notice the smeel when I use the freeway. Good to know that I haven't screwed up my cat.. A year ago when my car was running fine I kept getting o2 sensor codes. Since it started running bad a month ago I have only gotten misfire codes.. Still stuck on doing this myself. I don't want to ruin anything by messing with the manifold. But I don't want to take it to a shop either.

 

:Update: It was a coil. Thanks

 

Please gut your pre cats and save what's left of your engine.

 

Don't think that's necessary. I only drove it flashing twice, plus I pulled over as soon as it started.

 

Glad you fixed it

 

Thanks.. No more misfiring. But still turns back off after I first start it half the time like it has always done.. It's pretty weird I have no CEL anymore but eachtime i plug in my scan tool it gives me 3 of the same codes which are p1800 vias control, even though I have fixed the rod..