Newb questions about o2 sensor...
Newb questions about o2 sensor...
Ok, put this in the newbie question cause I'm still new to these cars and it maybe a dumb as$ subject. Sorry in advance if it is. To start, only mods are in my sig.
So the car used to give me a random hesitation/vibration around 75-80mph back in mid September on my way to Nopi. I'd let go of the throttle, car would be fine, then 30sec later, it starts again. I reset ECU by pulling battery and it's been fine since. Now I've heard of the P0300 code which gives you the random misfire, but the case typically gives you one hesitation w/the CEL, after you let off the throttle, it's fine. That happened to me a couple months ago also, and I had pulled the code, and that's the code it gave me (P0300). I changed plugs, bla bla, it was fine. NOW the continuous misfire symptom is back! The car set off the CEL and continues to hesitate/vibrate/sputter even after letting off the gas and getting back on the throttle only on the hwy at 75-80mph. At WOT it's fine.
Now this only happens once in a while, not all the time! Btw, coincidently this never happened before until I got my reflash back in Sept. It went away for a while since then, now it's back after recently installing a UR test pipe. I'm missing one gasket since the stock one was all coroded and broken. So I'm getting two new ones this week to put them right in. Yes, I have a major exhaust leak as a result. 
The hesitation that feels like a misfire only comes on the hwy in 5th gear...same as before. Yes, I regapped my Iridium plugs to .024 Sunday and I pulled the negative terminal on battery to reset the ECU, and the next hour the CEL came back when I turned on the car...in idle! It never did that before while in idle. Usually the light came on on the hwy cruising mode only. I was curious, so I took it to Autozone today and now the code is P0136 -- Heated Oxygen Sensor Circuit [SEMSOR 2]. No other codes. My boy who has alot of knowledge of Evos, said my front 02 sensor is damaged! How?...I don't know!? I thought it was the rear 02 sensor on the UR tp, but he says that one really doesn't do much, so it's the one from the 02 housing. The car runs fine regardless. It's just once in a while cruising in 5th gear, it starts vibrating/hesitating like a misfire. So could the 02 sensor result in that hwy vibration/sputter? Could it have been damaged the whole time since Sept but now suddenly back w/a new tp?? Can a reflash damage your 02 sensor???
Sorry so long. I just wanted opinions before spending $$$ I don't have!
So the car used to give me a random hesitation/vibration around 75-80mph back in mid September on my way to Nopi. I'd let go of the throttle, car would be fine, then 30sec later, it starts again. I reset ECU by pulling battery and it's been fine since. Now I've heard of the P0300 code which gives you the random misfire, but the case typically gives you one hesitation w/the CEL, after you let off the throttle, it's fine. That happened to me a couple months ago also, and I had pulled the code, and that's the code it gave me (P0300). I changed plugs, bla bla, it was fine. NOW the continuous misfire symptom is back! The car set off the CEL and continues to hesitate/vibrate/sputter even after letting off the gas and getting back on the throttle only on the hwy at 75-80mph. At WOT it's fine.
Now this only happens once in a while, not all the time! Btw, coincidently this never happened before until I got my reflash back in Sept. It went away for a while since then, now it's back after recently installing a UR test pipe. I'm missing one gasket since the stock one was all coroded and broken. So I'm getting two new ones this week to put them right in. Yes, I have a major exhaust leak as a result. The hesitation that feels like a misfire only comes on the hwy in 5th gear...same as before. Yes, I regapped my Iridium plugs to .024 Sunday and I pulled the negative terminal on battery to reset the ECU, and the next hour the CEL came back when I turned on the car...in idle! It never did that before while in idle. Usually the light came on on the hwy cruising mode only. I was curious, so I took it to Autozone today and now the code is P0136 -- Heated Oxygen Sensor Circuit [SEMSOR 2]. No other codes. My boy who has alot of knowledge of Evos, said my front 02 sensor is damaged! How?...I don't know!? I thought it was the rear 02 sensor on the UR tp, but he says that one really doesn't do much, so it's the one from the 02 housing. The car runs fine regardless. It's just once in a while cruising in 5th gear, it starts vibrating/hesitating like a misfire. So could the 02 sensor result in that hwy vibration/sputter? Could it have been damaged the whole time since Sept but now suddenly back w/a new tp?? Can a reflash damage your 02 sensor???
Sorry so long. I just wanted opinions before spending $$$ I don't have!
Jose, the following information is not what you want to hear, but here it goes:
After my Tilton install, at aprox. 26,000 miles, I started getting the PO300 code. Soon there after, the same thing that is now happening to you, started happening to me too. The service light would come on and the car would miss fire right after that, just like you describe, same mph too, same gear. I would let off the gas, and it would go away, then the process would repeat. I got 13,000 miles on the clutch now and the light still comes on a few times a day. To date, the mis fire still comes and goes, but only while the service engine light is on. It will not do it while is off. So I reset the light with my new code reader as soon as the light comes on. I have learned to live with this and with this new Gizmo, my life is much easier as I can reset the code in less than 15 seconds. Here is a link to the devise. It is the best investment I have made. I may have to live with the service light coming on every day, but I don't have to put up with the hick up for too long,
. http://www.scangauge.com/
As far as I have concluded, when the light comes on as a PO300 code, the car will actually mis fire. That is why we get that hick up. Either that, or the ECU actually goes into crazy mode and makes the car mis fire. It is a mistery, and many are getting it. John have experimented with my ECU and he was able to erase the code description, so when the codecomes on, is no longer a PO300 code but the light still is trigered. He is still working on a fix.
Don't worry about the miss fire, your car is fine. Just re set the ECU code and keep on driving. You can be driving and re setting the code at the same time. One word of caution, do not beat on it when the hick up is trigered. Get off the gas inmediatelly. You don't want to gas the car while the miss fire is going on. A mis fire is a mis fire and it is important to let off and re set the code as soon as possible.
I have changed the plugs and tried every gap possible. From .19 to .30.
At .19-.20, the car idles like crap, but has much better bottom end. At .29-.30, the car misses some times on the top rpms. I do have the HKS DLI II, so I can play with it like that without the lost of spark. I found that the car works best at .25. I believe that if you go below .25, you will actually be advansing the tuned timing a little and changing your current tune. So take the plugs out and re gap them to .25.
At least now you know the car is fine man. I boost pretty good and my car has not blown up yet in 2 1/2 years,
.
After my Tilton install, at aprox. 26,000 miles, I started getting the PO300 code. Soon there after, the same thing that is now happening to you, started happening to me too. The service light would come on and the car would miss fire right after that, just like you describe, same mph too, same gear. I would let off the gas, and it would go away, then the process would repeat. I got 13,000 miles on the clutch now and the light still comes on a few times a day. To date, the mis fire still comes and goes, but only while the service engine light is on. It will not do it while is off. So I reset the light with my new code reader as soon as the light comes on. I have learned to live with this and with this new Gizmo, my life is much easier as I can reset the code in less than 15 seconds. Here is a link to the devise. It is the best investment I have made. I may have to live with the service light coming on every day, but I don't have to put up with the hick up for too long,
. http://www.scangauge.com/As far as I have concluded, when the light comes on as a PO300 code, the car will actually mis fire. That is why we get that hick up. Either that, or the ECU actually goes into crazy mode and makes the car mis fire. It is a mistery, and many are getting it. John have experimented with my ECU and he was able to erase the code description, so when the codecomes on, is no longer a PO300 code but the light still is trigered. He is still working on a fix.
Don't worry about the miss fire, your car is fine. Just re set the ECU code and keep on driving. You can be driving and re setting the code at the same time. One word of caution, do not beat on it when the hick up is trigered. Get off the gas inmediatelly. You don't want to gas the car while the miss fire is going on. A mis fire is a mis fire and it is important to let off and re set the code as soon as possible.
I have changed the plugs and tried every gap possible. From .19 to .30.
At .19-.20, the car idles like crap, but has much better bottom end. At .29-.30, the car misses some times on the top rpms. I do have the HKS DLI II, so I can play with it like that without the lost of spark. I found that the car works best at .25. I believe that if you go below .25, you will actually be advansing the tuned timing a little and changing your current tune. So take the plugs out and re gap them to .25.
At least now you know the car is fine man. I boost pretty good and my car has not blown up yet in 2 1/2 years,
.
Last edited by 04AWDTURBOEVO; Oct 9, 2006 at 09:19 PM.
Well Manie, I appreciate the support as always. I did post on the OrlDSMForums a while back about the P0300 code and the CEL, but this case is different. It's the P0136 code now and the vibration happens like every 30seconds...not just the one time. Same mph on the hwy, and same feel, but just more often even after letting off the throttle. Again, doesn't happen consistently though. I just referred to the P0300 misfire cause that's the same hesitation/sputter I felt when I had it then. It's not pulling the misfire code anymore though, but that's what it feels like, just more often. That's why I was asking about the 02 sensor in the front, being that I got that code -- Heated Oxygen Sensor Circuit [SEMSOR 2].
I ordered the fuel pump, gonna get it reflashed again once it's in, get my 3" exhaust gaskets, then go from there. Ruben told me my front 02 sensor is shot, but I don't have money for that and I gotta make sure that's what it is for sure first.
Same mph on the hwy, and same feel, but just more often even after letting off the throttle. Again, doesn't happen consistently though. I just referred to the P0300 misfire cause that's the same hesitation/sputter I felt when I had it then. It's not pulling the misfire code anymore though, but that's what it feels like, just more often. That's why I was asking about the 02 sensor in the front, being that I got that code -- Heated Oxygen Sensor Circuit [SEMSOR 2]. I ordered the fuel pump, gonna get it reflashed again once it's in, get my 3" exhaust gaskets, then go from there. Ruben told me my front 02 sensor is shot, but I don't have money for that and I gotta make sure that's what it is for sure first.
Originally Posted by Talon
Got any pics of your GST?
Originally Posted by jqturbo
Here's mine:
Originally Posted by jqturbo
Well Manie, I appreciate the support as always. I did post on the OrlDSMForums a while back about the P0300 code and the CEL, but this case is different. It's the P0136 code now and the vibration happens like every 30seconds...not just the one time. Same mph on the hwy, and same feel, but just more often even after letting off the throttle. Again, doesn't happen consistently though. I just referred to the P0300 misfire cause that's the same hesitation/sputter I felt when I had it then. It's not pulling the misfire code anymore though, but that's what it feels like, just more often. That's why I was asking about the 02 sensor in the front, being that I got that code -- Heated Oxygen Sensor Circuit [SEMSOR 2].
I ordered the fuel pump, gonna get it reflashed again once it's in, get my 3" exhaust gaskets, then go from there. Ruben told me my front 02 sensor is shot, but I don't have money for that and I gotta make sure that's what it is for sure first.
Same mph on the hwy, and same feel, but just more often even after letting off the throttle. Again, doesn't happen consistently though. I just referred to the P0300 misfire cause that's the same hesitation/sputter I felt when I had it then. It's not pulling the misfire code anymore though, but that's what it feels like, just more often. That's why I was asking about the 02 sensor in the front, being that I got that code -- Heated Oxygen Sensor Circuit [SEMSOR 2]. I ordered the fuel pump, gonna get it reflashed again once it's in, get my 3" exhaust gaskets, then go from there. Ruben told me my front 02 sensor is shot, but I don't have money for that and I gotta make sure that's what it is for sure first.
But there is no need to pay $200.00 plus for a sensor. Go here, http://www.automedicsupply.com/index.php?ref=Google and buy it for less than $100.00. I hope this helps you, Jose.
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Originally Posted by 04AWDTURBOEVO
If the front 02 sensor is bad, it will sputter and have a hick up for sure, and often.
But there is no need to pay $200.00 plus for a sensor. Go here, http://www.automedicsupply.com/index.php?ref=Google and buy it for less than $100.00. I hope this helps you, Jose.
But there is no need to pay $200.00 plus for a sensor. Go here, http://www.automedicsupply.com/index.php?ref=Google and buy it for less than $100.00. I hope this helps you, Jose.
That would help alot for sure. Thanks so much! Ruben said they're about $250 or so...with a discount! 
The car's been running good other than the random cruise hwy speeds, but I'll keep ya posted!
Originally Posted by jqturbo
Well Manie, I appreciate the support as always. I did post on the OrlDSMForums a while back about the P0300 code and the CEL, but this case is different. It's the P0136 code now and the vibration happens like every 30seconds...not just the one time. Same mph on the hwy, and same feel, but just more often even after letting off the throttle. Again, doesn't happen consistently though. I just referred to the P0300 misfire cause that's the same hesitation/sputter I felt when I had it then. It's not pulling the misfire code anymore though, but that's what it feels like, just more often. That's why I was asking about the 02 sensor in the front, being that I got that code -- Heated Oxygen Sensor Circuit [SEMSOR 2].
I ordered the fuel pump, gonna get it reflashed again once it's in, get my 3" exhaust gaskets, then go from there. Ruben told me my front 02 sensor is shot, but I don't have money for that and I gotta make sure that's what it is for sure first.
Same mph on the hwy, and same feel, but just more often even after letting off the throttle. Again, doesn't happen consistently though. I just referred to the P0300 misfire cause that's the same hesitation/sputter I felt when I had it then. It's not pulling the misfire code anymore though, but that's what it feels like, just more often. That's why I was asking about the 02 sensor in the front, being that I got that code -- Heated Oxygen Sensor Circuit [SEMSOR 2]. I ordered the fuel pump, gonna get it reflashed again once it's in, get my 3" exhaust gaskets, then go from there. Ruben told me my front 02 sensor is shot, but I don't have money for that and I gotta make sure that's what it is for sure first.
Just scanned my car again, got:
P0141 (twice?)
P0171
P0300
P0136
As stated in my other thread, I KNOW that my rear O2 sensor is dead, without a doubt, but that shouldn't do anything but trigger the SES light from what I understand. Driveability shouldn't be harmed. Now I'm kind of thinking that maybe my front and rear is gone...?
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