Loss of Power / Misfire
my question(s) to everyone is
1. does your car start to stumble and have problems upon start up or does it do that when its warmed up? this will eliminate some things that could cause your problem.
2. how many miles are on your o2 sensors, optispark, coil, spark plugs, wires, ect. catch my drift? its called preventative maintaince.
3. have you recently installed headers? if so check your plug wire routing. they could be grounding out which will result in hesitation, poor idle and performance. listen for a tic sound coming from the wires. if you here it you'll also notice the motor stumble and shake violently. you can here a "lope" come from the motor as well. also look for an arc of electricity. easiest done at night.
4. have you changed your fuel filter at all? easy fix here gents. bad fuel filters will cause poor performance.
5. catalytic converters are notorious for causing motors to run like garbage. if you have a lot of mileage on your car chances are the cat is starting to go.
1. does your car start to stumble and have problems upon start up or does it do that when its warmed up? this will eliminate some things that could cause your problem.
2. how many miles are on your o2 sensors, optispark, coil, spark plugs, wires, ect. catch my drift? its called preventative maintaince.
3. have you recently installed headers? if so check your plug wire routing. they could be grounding out which will result in hesitation, poor idle and performance. listen for a tic sound coming from the wires. if you here it you'll also notice the motor stumble and shake violently. you can here a "lope" come from the motor as well. also look for an arc of electricity. easiest done at night.
4. have you changed your fuel filter at all? easy fix here gents. bad fuel filters will cause poor performance.
5. catalytic converters are notorious for causing motors to run like garbage. if you have a lot of mileage on your car chances are the cat is starting to go.
im bumpin this up there seems to be plenty of people with this problem. anyone have some insight yet? im putting my opti and new clutch in on monday so i'll letchya know what happens with that
TECH Apprentice
Joined: Sep 2007
Posts: 333
Likes: 0
my first question would be.. my car is throwing ses all the time. it's actually been on for a while but i got tired of taking it to autozone and deleting the codes. im pretty sure i was getting low voltage at the o2's. the guy i bought the car from was a real douchebag, and the car has a really weird exaust but it is true duals. the question is.. if my exaust is throwing these codes, could that be the reason its running like ****? i have a post on the first page of this thread that explains my symptoms. any help is appreciated
I keep the gas pedal in the same spot and the car will lag in accelerating, then all of the sudden it will just pick up and go like it should be. while its lagging the rpms will rise but at a slower rate. it seems to catch at about 4k. it almost makes me wonder if its a timing issue. i know my clutch isn't slipping because i just replaced it. im always throwing o2 codes but im not sure how that will apply to the problem im having.
well i changed my plug wires and it seems most of my problems went away except for hard starting and the occasional high idle. it misses every now and then but i suspect a bad opti. i went out and thoroughly inspected my wires and found they were cracking and the insulation was chewed up and upon removal of number 6 it literally fell apart in my hand. god changing wires sucks but so worth it. car is a whole new animal. depending on the age of your wires i suggest getting swapping them out for new ones especially if you just put headers on. it'd also be a hell of a lot easier if you did it during the installation of headers. that way running them would be easier.
well what have you done to try and fix the problem? i got plenty of suggestions just let me know what you've done so far. i just changed my opti and it runs a hell of a lot better. still got the occasional high idle still but thats most likely the idle air control.
really check your plug wires carefully. if they are cracked or aged just replace them. i can gurantee they or arching and grounding out
really check your plug wires carefully. if they are cracked or aged just replace them. i can gurantee they or arching and grounding out
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Verdad Gallardo I keep the gas pedal in the same spot and the car will lag in accelerating, then all of the sudden it will just pick up and go like it should be. while its lagging the rpms will rise but at a slower rate. it seems to catch at about 4k. it almost makes me wonder if its a timing issue. i know my clutch isn't slipping because i just replaced it. im always throwing o2 codes but im not sure how that will apply to the problem im having.
If you delete the AIR and EGR (if you have it) as well as get rid of that vacume manifold to the right of the intake manifold under the cowl. In fact, I would try unplugging all those lines going into it and see what happens. You can do that in the driveway in 15 minutes and see if thats the cause.
TECH Apprentice
Joined: Aug 2008
Posts: 369
Likes: 0
From: Greensboro NC or Miami Fl
I know what the problem is there is probably an air leak. That wasa causing the problem in my misfiring of the cyclinders check your hoses and see if you find the problem. It happen to me but my mechanic was smart enough to figure it out. It was throwing the 02 sensor and misfiring at the same time all it was is a hose that was bad that it.
I know what the problem is there is probably an air leak. That wasa causing the problem in my misfiring of the cyclinders check your hoses and see if you find the problem. It happen to me but my mechanic was smart enough to figure it out. It was throwing the 02 sensor and misfiring at the same time all it was is a hose that was bad that it.
i had a cracked spark plug that caused me to have a slight misfire and took forever to pinpoint it! it is also a possibility that new o2 sensors can be faulty and throw a code. when the o2 sensor throws a low voltage code meaning its running too lean the car will then make the engine rich like crazy just not to blow the motor and in that situation a possibility that the cat will get clogged on bank 1 or 2 and the spark plugs will be fouled from this. so dont drive like this for too long
mine still is doin this. it really feels low on power now too. it used to stumble at 1400-1500 and now i put 1.6rr on it and now it just stumbles at around 1700rpm when driving. after that it pulls harder but seems to have more in reserve just somethings holding it back. im going to seafoam my car today and check out other stuff. really aggravating because this thing should be holding me in the seat harder than it is.
Teching In
Joined: Mar 2007
Posts: 23
Likes: 0
From: Michigan
I know I am reviving a really old thread, but I fixed my problem and wanted to let everyone know what it ended up being. You can read through the thread for my symptoms. In the end, a new MAF did the trick. Kind of embarrassing that I drove it around for a couple years like that... Hahaha
Teching In
Joined: Jul 2007
Posts: 3
Likes: 0
same symptoms I have a 01 Ws6 w/140k miles with the same problem,the car bogged real bad to were my car would turn off,the car would turn on no problem but when i put in in gear it would bog down and turn off everytime. i had a similar case like it a few years back with the o2 sensor's so i thought i had it fixed when i changed them out. not long after changing them out car still bogged down and shut off on me heard a noise coming from the back of my car this time like a fuel pump going out bought a new fuel pump changed it out and the filter while i was down there took it for a ride an was running like a champ till about 30 minutes later. it starts with a real low backfire and would get stronger and louder to were i have to pull over.luckily i was on my way back an drove it home slowly. next day cleaned all connections to everywere with terminal cleaner cleaned my maf with the maf cleaner an sea foamed my intake manifold an gas tank still had the problem. so i took off my brother's coil packs off his Ws6 an taylor spark plug wire's and changed my spark plugs and put his coil packs an wires on my car an so far till this day no problems (KNOCK ON WOOD LOL) weird never had problems like this. 
I am having the same issue I put on my new msd wires, new front o2 sensor fuel filter & cleaned maf, & P&P TB, it's still has 2 codes P0303 & P0506 I have a little exhaust leak on my rear driverside header, & my ngk t55 plugs have 4k miles on them it's idle @ 500-650. I had the rear o2 deleted & egr, air, from HP tuners . On coil #3 where the mifire @ I unplug coil #3sensor & it still idle the same so I dis & Re connected battery. & put coil #3 sensor back on & took off #1 coil it still idle the same I have no idea left other then IAC idle air control
09-02-10
I bought a iac sensor & still no luck
09-02-10
I bought a iac sensor & still no luck
Last edited by ls1jorge; Sep 2, 2010 at 09:02 AM.
