or what else could it be?

 

anybody? the exhaust note has also changed.. its a bit more throaty

 

Is the Check Engine Light on?

 

Is the Check Engine Light on?

it wasnt when it started acting crappy. It is now that i unplugged the o2 sensor. I only drove it around a little with it unplugged so i dont know if it will turn off if i replug it.

 

try resetting your computer.

 

No CEL? hesitation when you put he pedal down? or does it hesitate then it goes? how does the car sound? hear any weird noises? which 02 sensor did you unplug front rear? not telling us much here...

 

No CEL? hesitation when you put he pedal down? or does it hesitate then it goes? how does the car sound? hear any weird noises? which 02 sensor did you unplug front rear? not telling us much here...

no CEL until i unplugged. A little hesitation and a lot of overall powerloss when i get on the gas. The car sounds a lot throatier and it bounces around (the engine) like an old muscle car. I unplugged the front o2 sensor and that made it run a bit better. No weird noises that i know of.

hope that helps

 

no CEL until i unplugged. A little hesitation and a lot of overall powerloss when i get on the gas. The car sounds a lot throatier and it bounces around (the engine) like an old muscle car. I unplugged the front o2 sensor and that made it run a bit better. No weird noises that i know of.

hope that helps

Unplugging the front o2 sensor will not make your car run better, if anything it will make it worse since the ECU since it needs to communicate with the o2 sensor constantly once the engine has reached operating temperature, your car runs of the front o2 once it warms up, it could might as well be the front o2 went bad, and the ECU is not detecting it.
Also, check your ECU plugs (engine bay, next to the battery it has been raining you know)it could mean that water got on them, and that's why it's hesitating and iddling rough. I would suggest unplugging them and run a hair driver on soft, and not directly on top of it, otherwise you will melt the rubbing ring aroung it, but about 10inches away, have you noticed a decrease in fuel mileage?

 

Unplugging the front o2 sensor will not make your car run better, if anything it will make it worse since the ECU since it needs to communicate with the o2 sensor constantly once the engine has reached operating temperature, your car runs of the front o2 once it warms up, it could might as well be the front o2 went bad, and the ECU is not detecting it.
Also, check your ECU plugs (engine bay, next to the battery it has been raining you know)it could mean that water got on them, and that's why it's hesitating and iddling rough. I would suggest unplugging them and run a hair driver on soft, and not directly on top of it, otherwise you will melt the rubbing ring aroung it, but about 10inches away, have you noticed a decrease in fuel mileage?

ill try that when i get home from work. and yea, the gas mileage sucks.

thanks

 

The shaking could be from misfiring. When's the last time you changed out the spark plugs or fuel filter? My car did the same thing and it just needed a tune-up. Just a thought, could be something else.

 

The shaking could be from misfiring. When's the last time you changed out the spark plugs or fuel filter? My car did the same thing and it just needed a tune-up. Just a thought, could be something else.

yeah i thought that but the spark plugs got changed couple thousand miles ago. ill take a look at the fuel filter also though.

 

The shaking could be from misfiring. When's the last time you changed out the spark plugs or fuel filter? My car did the same thing and it just needed a tune-up. Just a thought, could be something else.

You are right, but a cylinder misfire would be detected by the ECU, by a flashing CEL.

The ECU will give codes
p0301 (cyl 1)
p0302 (cyl 2)
p0303 (cyl 3)
p0304 (cyl 4)

how do I know? I had the very same problem lastweek, with my car and it turned out to be the ECU wires, I was getting all of the above codes.

But you are right about the misfire, those are the symptoms.
Rommel, check for spark within your plugs, check the plug wires could be a bad connection at the coilpack.

 

check for exposed wiring. if that gets wet it will cause issues. as people have stated the front 02 sensor is used by the car to determine fuel trims operating stuff, and open/closed loop stuff. if the sensor died the mileage will sick cause the car will try and compensate for the bad sensor.

replace the frotn o2 sensor would be my best guess. i have been tinkering with mine alot recently, and when the AFRs get to high the engine will knock, and the ecu will retard timing to keep it from blowing up. also the lean afrs cause the car to idle VERY low and spartically. for instance my car was idling at 17/1 AFR this morning. the needle would bounce around uner 1k rpms, and get very close to dieing.

with AFRs to low the car will bog down both on the road and at idle. since it is gettig too much fuel (heres how i enterprete this stuff, prolly wrong, so pls correct me) when you get down into the 9/1 and lower AFRs you are adding way to much liquid fuel to the combustion chamber and it cools the chamber down too much for a proper ignition. you can have rich misfires where he is too much gas and it wont ignite giving you a misfire. also too much liquid fuel will cause hesitiation. becareful cause too much liquid fuel will soak the clinder walls (bad).

just my .02 hehe. wow i am fairly impressed i just picked up all this knowledge from experience in the last week or so..

good luck

 

I'm also having misfire/idle problems. I'm getting CEL misfire codes on all 4 cylinders and also a PO170 code (Fuel Trip Malfuction Bank 1). Anyone know what a Fuel Trip Malfuction is?

I replaced the plugs and wires about 3000 miles ago and just had my timing belt, timing belt tensioner, and drive belts replaced.

The really strange thing is that since my car has been acting this way I've been getting better gas milage than normal. I usually get around 300 miles on a full tank, now I'm getting around 330-340 miles on a full tank.


Anyway, this is starting to drive me crazy.

 

I'm also having misfire/idle problems. I'm getting CEL misfire codes on all 4 cylinders and also a PO170 code (Fuel Trip Malfuction Bank 1). Anyone know what a Fuel Trip Malfuction is?

I replaced the plugs and wires about 3000 miles ago and just had my timing belt, timing belt tensioner, and drive belts replaced.

The really strange thing is that since my car has been acting this way I've been getting better gas milage than normal. I usually get around 300 miles on a full tank, now I'm getting around 330-340 miles on a full tank.


Anyway, this is starting to drive me crazy.

Sounds like a fuel issue, perhaps your fuel pump?

 

Also, check your ECU plugs (engine bay, next to the battery it has been raining you know)it could mean that water got on them, and that's why it's hesitating and iddling rough. I would suggest unplugging them and run a hair driver on soft, and not directly on top of it, otherwise you will melt the rubbing ring aroung it, but about 10inches away, have you noticed a decrease in fuel mileage?

hehe, these are not located by the battery on a stock RS. This is a WRX thing. They will be (when facing the car) on the left side of the motor at the very top(there are like 3 of them) on the tranny side held in by a bracket that is attatched to the top engine bolt, underneath the airbox. With that being said I highly doubt that is the issue. Without any CEls its hard to pinpoint the problem. What year is your car? My guess would also be 02 sensor

 

hehe, these are not located by the battery on a stock RS. This is a WRX thing. They will be (when facing the car) on the left side of the motor at the very top(there are like 3 of them) on the tranny side held in by a bracket that is attatched to the top engine bolt, underneath the airbox. With that being said I highly doubt that is the issue. Without any CEls its hard to pinpoint the problem. What year is your car? My guess would also be 02 sensor

Look at the big brain on Keen4r!!! actually if it's anyone who would know is you...what is this world coming to??? when you are corrected by Keener, I think I am going to crawl under a rock and die now...

 

Look at the big brain on Keen4r!!! actually if it's anyone who would know is you...what is this world coming to??? when you are corrected by Keener, I think I am going to crawl under a rock and die now...

teehee!

 

just an update to finish this thread... the dealer that screwed me over (see old topic) also did not install the timing belt correctly and the belt on the left cam shaft was two teeth off. so yah.. they should die. i got it fixed and now it runs perfectly!

 

just an update to finish this thread... the dealer that screwed me over (see old topic) also did not install the timing belt correctly and the belt on the left cam shaft was two teeth off. so yah.. they should die. i got it fixed and now it runs perfectly!

schweet! :banana: