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Got a evo 8 and at the moment is running extremely rich.
Have done a boost leak and no leaks found,also changed plugs as well to no avail.
No DTC showing
Opened up EvoScan and was looking at the reading on the upstream 02 sensor and voltage was fluctuating 0.81v -0.85v and only ever dipping into the 0.75v once in the 1min log I was did.
is this normal,engine temp was around 85degrees,and was under the impression it should fluctuate more frequently and lower volts then 0.75 it was showing.
is this a sign of a bad or lazy 02sensor?or do I have a issue else where.
cheers
Last edited by cprevo; Feb 25, 2021 at 04:32 AM.
Reason: Video
Got a evo 8 and at the moment is running extremely rich.
Have done a boost leak and no leaks found,also changed plugs as well to no avail.
No DTC showing
Opened up EvoScan and was looking at the reading on the upstream 02 sensor and voltage was fluctuating 0.81v -0.85v and only ever dipping into the 0.75v once in the 1min log I was did.
is this normal,engine temp was around 85degrees,and was under the impression it should fluctuate more frequently and lower volts then 0.75 it was showing.
is this a sign of a bad or lazy 02sensor?or do I have a issue else where.
cheers
Other than the log you did, what other symptoms do you have that indicate its running rich? Raw fuel smell or bad MPG without hard driving? Stuff like that.
Im also guessing 85 degrees Celsius as in the engine is at operating temp correct?
Is the car modded and if so is it on MAF or speed density tune?
[QUOTE=slocho;11930934]Other than the log you did, what other symptoms do you have that indicate its running rich? Raw fuel smell or bad MPG without hard driving? Stuff like that.
Im also guessing 85 degrees Celsius as in the engine is at operating temp correct?
Is the car modded and if so is it on MAF or speed density tune?[/
Yep car is modded and still running MAF.
85 Degrees Celsius is what coolant temp sensor showing on EvoScan.
Im having numerous issues with this car
-When driving and coming to a stop it tends to stall
-blows black smoke when hitting boost(After say 2miles of driving and boosting it tends to clear up)
-When starting engine up,it starts straight away but tends to cough for about 10seconds or so
-idle is never steady,drops or rises a few hundred RPM
-At idle it will idle say 1000rpm then drop to 500rpm and if it doesn’t stall when go back to 1000rpm.
What I have done to fix it
-Replaced spark plugs
-boost leak test,a few leaks found and repaired but didn’t fix issue
-replaced coil pack with another evo that is fine and no luck
-replaced iacv with a new oem one
i do have to say,when in EvoScan and activating SAS to set the new iacv,the idle drops to 500rpm and no matter how far back I wind the biss screw out it won’t rise the idle.
sorry for long post just wanna be as accurate as I can as this will be important
if the car was running fine... and all of a sudden its pig rich at idle...
front o2 is bad
It was running fine until I replaced dump pipe and fixed a few other issues around the engine bay.Since then it hasn’t run the same.
triple checked everything and everything is in place and connected.
Maybe I disturbed the 02 sensor when swapping it over is the only thing I can think off,but I’m not getting a engine light or any codes when scanning vehicle up
Other than the log you did, what other symptoms do you have that indicate its running rich? Raw fuel smell or bad MPG without hard driving? Stuff like that.
Im also guessing 85 degrees Celsius as in the engine is at operating temp correct?
Is the car modded and if so is it on MAF or speed density tune?[/
Yep car is modded and still running MAF.
85 Degrees Celsius is what coolant temp sensor showing on EvoScan.
Im having numerous issues with this car
-When driving and coming to a stop it tends to stall
-blows black smoke when hitting boost(After say 2miles of driving and boosting it tends to clear up)
-When starting engine up,it starts straight away but tends to cough for about 10seconds or so
-idle is never steady,drops or rises a few hundred RPM
-At idle it will idle say 1000rpm then drop to 500rpm and if it doesn’t stall when go back to 1000rpm.
What I have done to fix it
-Replaced spark plugs
-boost leak test,a few leaks found and repaired but didn’t fix issue
-replaced coil pack with another evo that is fine and no luck
-replaced iacv with a new oem one
i do have to say,when in EvoScan and activating SAS to set the new iacv,the idle drops to 500rpm and no matter how far back I wind the biss screw out it won’t rise the idle.
sorry for long post just wanna be as accurate as I can as this will be important
I would start off by pulling the MAF off and cleaning the element with electrical cleaner. If nothing, then i would check fuel pressure.
If there is a chance the primary 02 sensor was damaged, that would be the first part id replace after doing the first checks. From the sound of it, spark doesnt seem to be the issue.
I havent had an issue with my MAF sensor but i know those can cause really bad drivability issues when they fail, and some cases dont even set a code. Although i do not know what the spec would be if using a log, maybe someone else can answer that one.
if you wideband is reading in the 10's and 11's at idle.... its the front 02 sensor...
they are finicky.. sometimes just unbolting them they will fail.
I would start off by pulling the MAF off and cleaning the element with electrical cleaner. If nothing, then i would check fuel pressure.
If there is a chance the primary 02 sensor was damaged, that would be the first part id replace after doing the first checks. From the sound of it, spark doesnt seem to be the issue.
I havent had an issue with my MAF sensor but i know those can cause really bad drivability issues when they fail, and some cases dont even set a code. Although i do not know what the spec would be if using a log, maybe someone else can answer that one.
Yep have cleaned the MAF sensor to no avail.
Also swapped my coil packs with another evo and made no difference.
Been searching and unfortunately can’t read Fuel pressure with evoscan
if you wideband is reading in the 10's and 11's at idle.... its the front 02 sensor...
they are finicky.. sometimes just unbolting them they will fail.
unfortunately I don’t have a wideband and something I’m going to invest in one very soon.
I’m thinking it’s 02 sensor as it’s very stable at 0.8 and doesn’t bounce up and down from the thousands of videos I have checked on online(although some videos can be misleading)
In process of replacing 02sensor now(getting desperate now),removed old one and was literally covered in carbon.(layers of carbon)
unfortunately I put my hands on it and it wiped off to take any pictures of it.
Not sure what to make of that,either way ordered one and going to be replaced.
In process of replacing 02sensor now(getting desperate now),removed old one and was literally covered in carbon.(layers of carbon)
unfortunately I put my hands on it and it wiped off to take any pictures of it.
Not sure what to make of that,either way ordered one and going to be replaced.
Hopefully it fixes the issue. From the other comments it seems very likely it is the front 02. The primary 02 on my Acura RSX was out and it ran really poor. Felt like it was missing half the horsepower. Once replaced, it was waaay better.. back to normal.
Hopefully it fixes the issue. From the other comments it seems very likely it is the front 02. The primary 02 on my Acura RSX was out and it ran really poor. Felt like it was missing half the horsepower. Once replaced, it was waaay better.. back to normal.
I hope it’s a success after the 02 swap.
what made you believe it was the 02 sensor on the Acura?
I’m having normal power but stalling/rough idle and black smoke.If you stand behind the car it’s it’s really heavy fumes which makes it hard to breath(like a diesel)
I hope it’s a success after the 02 swap.
what made you believe it was the 02 sensor on the Acura?
I’m having normal power but stalling/rough idle and black smoke.If you stand behind the car it’s it’s really heavy fumes which makes it hard to breath(like a diesel)
My car had set a code, primary 02 stuck high i think. My symptoms were severe lack of power, poor running while driving (would almost feel like misfire while accelerating) and it would not hit VTAAK LOL. MPG did suffer but it was not terrible.
