marshallc

what happened - long story short, driving spiritedly made a left turn with a dip, car became much louder through out the whole rpm range, instead of the intake being silent up till 4k rpm it was loud through out the whole rpm range, with no change in tone at 4k rpm.


went home, took it to work the next day and out after that, put a solid 70 miles on it, car was louder, no noticiable intake change over at 4k rpm like before, started to bog worse and worse through out the day till the car died

What i have done so far...---
pulled a maf low input code and a iat one, replaced the maf with a new one, same ****

replaced the fuel pump, same ****.

let the car idle and unplugged the coilpacks one by one, idled rougher after each one was unplugged.

my observations/ car behavior....

my exhaust usualy has a slight burble at idle (removed stock resinator) now it is completely silent.

car throws a code for a random misfire, and a cyl 3 misfire

at a dead stop the car will rev till 3k rpm bogging the whole way, trying to drive it it bogs horibly, bounces all over, after a 1 mile drive the service engine soon light flash's (something with the cats?)


someone please help me!

Ritz

iTrader: (2)

describe the sound or lack of sound you're talking about more...

what intake do you have? you mean it seems to "scream" the entire RPM range, sorta like it does up top? can you hear anything like metal on metal?

you have a catback exhaust or just removed the resonator? what do you mean by "silent"? just not as loud?

try pulling your sparkplug in cyl 3 and see if it's soaked or looks like crap.. when were the plugs changed last, if at all?

how many miles do you have?

don't go changing random parts like that (unless you like spending tons of money) when it's giving you codes that are unrelated.. almost sounds like the timing is off, but I don't know why you'd only get a misfire on cyl 3....

also, the last thing you said about being at a dead stop... you mean in neutral if you just rev it up it bogs? as well as when driving?

try not to drive it, if possible.

chernmax

iTrader: (15)

I had a similar cylinder misfire code and it turned out that one of my fuel injector plugs were not snapped in properly on the back fuel bank (against the firewall) which made my car ride like **** and throw a similar code. It got loosened by me when I installed the plenum spacer. Once I plugged it back in, I reset the ECU (with my OBD-II) and the car ran great again. Oh and I also did a thorough check and finally found it on the 3rd check of the engine!!!

NmexMAX

iTrader: (22)

I'm guessing coil packs or, as chern said, injectors.

Most likely coil packs though.


Coil packs = plural, because that is what a flashing SES light indicates. How are the spark plugs?

marshallc

plugs were replaced around 90k miles has 106k now



i have an altima 3.5 intake with a k&n filter, sounds very similar to the fujita, pretty quiet till 4k rpm then when the 2nd intake runners open up it screams, now its loud as hell through out the whole rpm range, no metal on metal sound other than the usual start up rattle that ive experenced since i baught the car.

i was told that a flashing ses means that the cats are over the normal opperating temp


just removed the stock resinator, and the car use to have a nice burble at idle, now it makes no noise at all, if it didnt idle like **** i wouldnt even know the car were on



yes at a dead stop in neutral, the ammount of throttle that would usualy rev it till 3k rpm will bairly bring it past 1k, takes more than half throttle to get it to slowly go to 3k rpm and when it does it bogs even worse

NmexMAX

iTrader: (22)

Who told you that?

I would check the codes again.

KRRZ350

iTrader: (29)

he's sorta right, it means that the cat's will soon be destroyed by raw fuel.


WOW! So many poor suggestions in this thread........

Go to sears, buy a vacuum gauge, connect it/tee into a vacuum port on the manifold. Start car and watch reading. Race engine and watch reading after it drops back down. I'm almost certain that you will see your vacuum begin to slowly drop way beyond an acceptable level. That would indicate a badly restricted exhaust. ibumeltedacat.........

NmexMAX

iTrader: (22)

http://forums.maxima.org/showpost.ph...7&postcount=12

Point: Even if it is a cat converter, that's not the root cause of the problem.

Ritz

iTrader: (2)

so many poor suggestions? to be honest, I'd say yours is one of the worst, and potentially most dangerous to do with him not knowing much about the problem yet.

the first thing I would do is definitely NOT rev the hell out of the car.

KRRZ350

iTrader: (29)

hahaha, where did I mention that he should 'rev the hell out of the car'? I suggested he properly diagnose the problem instead of throwing parts at it, and yes I am aware that you did the same. Good job buddy Revving the engine is not going to harm the car, revving the hell out of it may, I did not suggest he do that, please re-read before you make comments like that. You apparantly jumped to the conclusion that by 'race the engine' I meant 'rev the hell out of it until it blows up', that was wrong on your part. Now, have you ever read the FSM? They suggest racing the engine in many pages, and they usually give an rpm specification and time length to do so, maybe I should have done that.......

"with the help of an assistant if your vacuum line isn't long enough to reach in the car, momentarily race the engine several times to 3500 rpm and moniter the vacuum reading afterwards"

Hahaha, one of the worst? Hummmm, that's funny, ok buddy, instead of asking him for more symptoms why don't you suggest a simple check he could make to properly diagnose the problem?

KRRZ350

iTrader: (29)

That is very true nmex. I wasn't going to mention that he needs to make sure that there wasn't a specific problem that caused the cat/cats to fail until after he posted back some vacuum readings and started tearing into his exhaust. However there is no point in trying to diagnose a misfire or fuel problem when there are mechanical problems that need to be attended to first. I geuss I will mention that now:

If the vacuum reading and then a visual check indicates a clogged/melted pre-cat or cat, after replacing you need to verify that you aren't running pig rich due to a fuel injection or ignition system problem.

It should also be mentioned that the catalytic convertors are covered under a longer federal emmisions system warranty.

marshallc

already did that, its a a steady 17hg at idle, and after revving.


i figured the maf reading = over oiled the filter, got one for 50 off ebay, so figured what ever, 50 bucks instead of 300+ for one from teh dealer, same with the fuel pump.

madmik

iTrader: (1)

What if your y-pipe touched the ground in that curve/dip. Could one of the primary cat's honeycomb have broken in pieces due to the shock and some loose pieces blocked the exhaust? That could cause that side of the exhaust to overheat and trigger a cat sensor code. Could explain the lack of power and the very quiet exhaust.

NmexMAX

iTrader: (22)

This is the most logical explanation from the situation you experienced.Note: Check pre-cat and other exhaust components.
Possible causes for blinking SES light from FSM.
Process of elimination?

All of these will cause damage to the cat.

marshallc

i think im just going to turn it over to the nissan dealer as im not having much luck on my own, hopfully they dont forget the lube :x