car information: 1997 se - 120k automagic trans
Mods: kn filter, wsp ypipe, stock cat 2.5 catback w/ flowmaster 40
maint: brand new spark plugs, fuel filter, battery

Problem: Lately my car has been shaking and wanting to die badly (It actually did one time) if i dont give it atleast 5-10 minutes to warm up. This has became a big problem now that winter is coming and sometimes i'm late and dont have enough time to let this car run, i should be able to start up and go :[


Possible problem: The one little sensor that would plug into the stock airfilter is unplugged because i have no where to put it into inless i make my own midpipe because of the k&n filter , i was told this didnt matter at all to the car from the dealership and some other sources but am i wrong? [coolant temp sensor?]

Culprits?: new pcv valve? cleaning the starter out?(About 7 years old now), someone told me possibly a bad cat..it is stock but i never thought that could cause a car to act like that.

I need opinons or somewhere to start from the .org before i go and spend money taking this in. I know ive posted this twice already and now this is the third time, but its as if my posts are ignored..I've tried to include everything both times. If i had experience this problem could be easier but im only 17 and this IS my only transportation lol. Thanks for any input you guys can give me after taking the time to read this.

 

1. The starter has nothing to do with how the car runs once it has started (other than if the starter gear in not disengaging from the flywheel)... but thats no the point
2. What is the idle speed when you notice this shaking?
3. Is your CEL lit? If yes, what were the codes?
4. Did you use NGK spark plugs?

 

How new is that K&N filter? Did you clean it recently? Sometimes people put too much oil on it and it clogs up the MAF sensor. Might need to clean the sensor with some rubbing alcohol and q-tips.

 

When i start the car up it starts at about 1500 rpms then will shortly fall to about 700-800.

Yes i used the NGK platinumss [forgot the # but it was correct].

The K&N is fairly new and its not a flat panel filter, i can visibly always see it and does look pretty clean, but I'll look at how the maf sensor looks.

The CEL code that nissan gave me was possibly a p105? i forget, Absolute pressure sensor though. No clue what it does either cant find anything on it.

Thanks for the tips and trying to help so far

 

Can a bad cat cause this? 120k miles, kind of noticing a hiss lately, I'm thinking its shot

 

I am experiencing the same problem that you are experiencing....I will start the car, and the RPMs will drop and bounce from 500-1000 RPM until the car is warmed up...I am going to do a bunch of maintenance things on my car. I suggest replacing the PCV valve, and cleaning out your IACV. My knock sensor is shot, so that may be the culprit too. My car is shaking cause I have multiple misfire, so check for that too....other than that I don't know. Hope you fix it too, and post what it was....maybe mine's the same.

 

My tuneup was awful because of the way my dad had handed down the car. 117 stock plugs. The rubber on the coil had fallen off in the 6th cylinder so i had a misfire for a few days, the 2 places i took it too told me atleast 500 in labor for them to fix the last plug because i had left the rubber off of a spark plug wrench because i did it myself (Didnt even touch the hole because i was smart enough to look into the hole before doing anything!) Had to hop on my car with the longest pair of needle nose pliars i could find and be patient, finally got it. Just did my knock sensor 2 months ago, my car shook like a v8 camaro with the bad plugs (3 were fried 6th was almost fully cracked so i had caught it just in time).

My coolant temp sens is danging because i dont have anywhere to stick it in inless i make my own pipe, which i think im on the way to doing. Im going to order that pcv valve inless i can just get it at napa. But where exactly is the IACV, I've read the stickies but am still unsure exactly where it is.