ECU reset
10-09-2002, 05:50 PM
#1
Cruisin'
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ECU reset
Over the last two months i changed my exhaust and put in a new intake, but i didn't reset my ecu until this past weekend, for those of you who've done something similar and haven't reset the ecu, its a must do. my car feels a lot quicker and smoother.
No doubt.....gotta do!!!!! Some say no but it's a must.....
10-09-2002, 06:39 PM
#3
2ManyMiles
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Really? A couple guys on here adamantly say that there's no difference between resetting it and not. I started a thread asking this a couple weeks ago and got a strong response not to do it.
I guess I'm gonna do it just to be safe when I get my mods done.
I guess I'm gonna do it just to be safe when I get my mods done.
10-09-2002, 07:10 PM
#7
Cost Drivers!!!!
Originally posted by Nashua_Night_Hawk
I installed the OBX headers and I did not reset the ECU and saw 40WHP gainon back to back dynos!... it does not matter.
I installed the OBX headers and I did not reset the ECU and saw 40WHP gainon back to back dynos!... it does not matter.
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10-09-2002, 07:39 PM
#8
Suzuka Master
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When resetting the ECU in this car the only thing that gets reset are the FT values. There are no other values other than potential DTCs which might be cleared.
Now, if you reset the FT tables you will be back at square one within minutes. It seems that many people think something magical happens when you reset the ECU. But that is a failure to realize how quickly the ECU adjusts and normally does so for the better.
Case in point, last Friday I was monitoring my ECU values on my laptop looking for clues to my recent DTCs. While idling in the garage for almost thirty minutes, obviously through an entire warm up cycle, the LTFT was at -8%. I drove about a mile down the road and the LTFT had adjusted to -3%. That is a 5% change in fuel delivery within two minutes. That difference can be between running 13.0:1 AF versus 12.4:1 AF. That might make an instant difference in feel but it would be quickly negated by the ECU.
We should be glad the ECU adjusts so well because it does help keep the car running well through a variety of conditions. This is how modern cars get 30 MPG and make 300 HP. That was unheard of years ago but nearly commonplace now.
But there is room for a little more power from the ECU. Typically the mixture runs a bit rich and leaning it out up high might give you a little more power. If you try to adjust that all of the time the ECU will trim that out; however, if you adjust it at the mid to upper revs when the ECU is in Open Loop mode then you might have a few ponies to gains. But fortunately/unfortunately we can't gain the power like was possible ten to fifteen years ago. They are tuned very well from the factory and adjust quickly.
As a disclaimer, this does not include factory turbo vehicles with ECU controlled boost. That is an entirely different topic and unrelated to our NA vehicles.
Now, if you reset the FT tables you will be back at square one within minutes. It seems that many people think something magical happens when you reset the ECU. But that is a failure to realize how quickly the ECU adjusts and normally does so for the better.
Case in point, last Friday I was monitoring my ECU values on my laptop looking for clues to my recent DTCs. While idling in the garage for almost thirty minutes, obviously through an entire warm up cycle, the LTFT was at -8%. I drove about a mile down the road and the LTFT had adjusted to -3%. That is a 5% change in fuel delivery within two minutes. That difference can be between running 13.0:1 AF versus 12.4:1 AF. That might make an instant difference in feel but it would be quickly negated by the ECU.
We should be glad the ECU adjusts so well because it does help keep the car running well through a variety of conditions. This is how modern cars get 30 MPG and make 300 HP. That was unheard of years ago but nearly commonplace now.
But there is room for a little more power from the ECU. Typically the mixture runs a bit rich and leaning it out up high might give you a little more power. If you try to adjust that all of the time the ECU will trim that out; however, if you adjust it at the mid to upper revs when the ECU is in Open Loop mode then you might have a few ponies to gains. But fortunately/unfortunately we can't gain the power like was possible ten to fifteen years ago. They are tuned very well from the factory and adjust quickly.
As a disclaimer, this does not include factory turbo vehicles with ECU controlled boost. That is an entirely different topic and unrelated to our NA vehicles.
10-09-2002, 07:57 PM
#9
PACDAT
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Originally posted by Zapata
cripes will you STOP quoting that 40whp gain!!!!! Complete and utter BS, you know it too. Explain to me how comptech ripoff is making more HP?
cripes will you STOP quoting that 40whp gain!!!!! Complete and utter BS, you know it too. Explain to me how comptech ripoff is making more HP?
10-09-2002, 08:12 PM
#10
Happy CL-S Pilot
I only saw the gains from the dyno graphs... I did not invent them... I did not even do the dyno myself... Gary Wang is the Mech who mounted my CLS on the dyno and he was behind the wheels when he dynoed? no wonder he was like 
when he saw the results.
Zapata, How come Mike saw 36 WHP gains from the CT headers with just CAI? could you explain that?
If you still doubt my numbers my CLS is still available anytime for a dyno just foot the bill... Okay?
when he saw the results.Zapata, How come Mike saw 36 WHP gains from the CT headers with just CAI? could you explain that?
If you still doubt my numbers my CLS is still available anytime for a dyno just foot the bill... Okay?
10-09-2002, 11:12 PM
#11
Instructor
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why do some of you get so defensive about the comptech vs OBX header discussion. are you mad because you paid tripple for the same thing? or is it just that you feel comptech is the best aftermarket tuning company in the world and nothing can match it?
10-10-2002, 11:56 AM
#12
Cruisin'
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Reseting the ECU is worth a shot, just let the car sit there with the battery unhooked for about 3-5 hours and see for yourself. my car feels a lot better. i've never experienced my car with so much torque steer and peels in 2nd gear.
10-10-2002, 12:06 PM
#13
Cost Drivers!!!!
MiK3Y,
Has nothing to do with how much i paid. If somebody can get the same performance for less then great! My gripe is with the actual numbers. Nashua goes around like the dyno #'s are golden when he really shouldn't. The numbers look funny. If you can't and he can't see that then you have your heads in the ground.
NNH,
NitrotigerCLS Is running 14.6 in a stock CLS in 70 degree weather. He'd be in the 14.4 range in 32 degree weather. My point.....the exception isn't the rule.
Nobody else has been able to match Mikes dyno. You could say that his car has the magic fairy dust. Could yours? Sure but how is that your 1/4 #'s are average before? You can argue that the 1/4 times and dyno #'s don't have a direct correlation but there is a relationship.
I'm not footing the bill man
I just disagree with the gains as the initial dyno is way too low for cls with your mods. It casts a shadow of a doubt. If you want to believe 40hp gain 
then go right ahead.....i'm just setting the record straight so the facts don't become some sort of truth when they aren't.
Has nothing to do with how much i paid. If somebody can get the same performance for less then great! My gripe is with the actual numbers. Nashua goes around like the dyno #'s are golden when he really shouldn't. The numbers look funny. If you can't and he can't see that then you have your heads in the ground.
NNH,
NitrotigerCLS Is running 14.6 in a stock CLS in 70 degree weather. He'd be in the 14.4 range in 32 degree weather. My point.....the exception isn't the rule.
Nobody else has been able to match Mikes dyno. You could say that his car has the magic fairy dust. Could yours? Sure but how is that your 1/4 #'s are average before? You can argue that the 1/4 times and dyno #'s don't have a direct correlation but there is a relationship.
I'm not footing the bill man
I just disagree with the gains as the initial dyno is way too low for cls with your mods. It casts a shadow of a doubt. If you want to believe 40hp gain then go right ahead.....i'm just setting the record straight so the facts don't become some sort of truth when they aren't.
10-10-2002, 12:12 PM
#14
Cost Drivers!!!!
Scalbert,
I won't challenge the hard data from the cpu link but all i can say is i drove around for 1 week after headers/exhaust/spark plug installed and drove like a MADMAN. I lived in the 3500-7000 range. Two gas fill ups and trip to the track. Weather conditions were consistant throughout the week. Each fillup was when the fuel light came on......343 miles. I couldn't get that shit driving with just my CAI. I was averaging around 300 at the time. 43 mile increase with headers/exhaust/spark plugs?? In addition my pipes were CLEAN as a whistle and mean as clean as when they were installed. How can that be possible??? My fuel source didn't change as i goto the same gas station everytime i fill up. Only after reseting the ECU did the fuel consumption and exhaust soot match my mods.
I won't challenge the hard data from the cpu link but all i can say is i drove around for 1 week after headers/exhaust/spark plug installed and drove like a MADMAN. I lived in the 3500-7000 range. Two gas fill ups and trip to the track. Weather conditions were consistant throughout the week. Each fillup was when the fuel light came on......343 miles. I couldn't get that shit driving with just my CAI. I was averaging around 300 at the time. 43 mile increase with headers/exhaust/spark plugs?? In addition my pipes were CLEAN as a whistle and mean as clean as when they were installed. How can that be possible??? My fuel source didn't change as i goto the same gas station everytime i fill up. Only after reseting the ECU did the fuel consumption and exhaust soot match my mods.
10-10-2002, 01:18 PM
#15
Senior Moderator
needing to reset the ecu is a myth.
but if you want to do it you don't need to leave the batt unhooked for hours on end. just disconnect the battery terminals and hold the + and - together for 15 seconds. then the ecu is reset.
i swear, some of the things i read on this site make me laugh.
but if you want to do it you don't need to leave the batt unhooked for hours on end. just disconnect the battery terminals and hold the + and - together for 15 seconds. then the ecu is reset.
i swear, some of the things i read on this site make me laugh.
10-10-2002, 02:37 PM
#16
Burning Brakes
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Well...
Scalbert has a point,
But I guess to put it in layman's terms
Reseting the ECU by pulling power (fuse, battery, etc.) is just a quicker way of what the ECU is going to do anyways. The car will eventually learn how to operate with it's new toy's (in regards to headers, or CAI) even if youy don't reset the ECU.
But I guess to put it in layman's terms
Reseting the ECU by pulling power (fuse, battery, etc.) is just a quicker way of what the ECU is going to do anyways. The car will eventually learn how to operate with it's new toy's (in regards to headers, or CAI) even if youy don't reset the ECU.
10-12-2002, 10:18 AM
#17
Pro
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Originally posted by Zapata
Scalbert,
I won't challenge the hard data from the cpu link but all i can say is i drove around for 1 week after headers/exhaust/spark plug installed and drove like a MADMAN. I lived in the 3500-7000 range. Two gas fill ups and trip to the track. Weather conditions were consistant throughout the week. Each fillup was when the fuel light came on......343 miles. I couldn't get that shit driving with just my CAI. I was averaging around 300 at the time. 43 mile increase with headers/exhaust/spark plugs?? In addition my pipes were CLEAN as a whistle and mean as clean as when they were installed. How can that be possible??? My fuel source didn't change as i goto the same gas station everytime i fill up. Only after reseting the ECU did the fuel consumption and exhaust soot match my mods.
Scalbert,
I won't challenge the hard data from the cpu link but all i can say is i drove around for 1 week after headers/exhaust/spark plug installed and drove like a MADMAN. I lived in the 3500-7000 range. Two gas fill ups and trip to the track. Weather conditions were consistant throughout the week. Each fillup was when the fuel light came on......343 miles. I couldn't get that shit driving with just my CAI. I was averaging around 300 at the time. 43 mile increase with headers/exhaust/spark plugs?? In addition my pipes were CLEAN as a whistle and mean as clean as when they were installed. How can that be possible??? My fuel source didn't change as i goto the same gas station everytime i fill up. Only after reseting the ECU did the fuel consumption and exhaust soot match my mods.
For example, if it takes you 10HP to drive at 60MPH (hypotheticaly), but the exhaust is restricting the output, and the sucks up 1 HP to push it out, then you need 11HP at the engine to get that 10HP to the wheels. That's extra fuel being burnt for nothing.
Scalbert is right though. All the ECU reset is doing is re-initializing the fuel trim tables. Unplug a sparkplug, drive for a bit, and then plug it back in. If you don't reset the ECM, then it'll take a bunch of miles for it to bring itself back into tune.
For mods, you need get the fuel/ignition tables changed to better use the extra air going through the engine. And right now, there are no aftermarket programmers for our ECU.
NOTE:
THE EXCEPTION: If you swap out really bad plugs (i.e. gap is burnt way over spec), then reseting the ECU will see a benefit, since the computer is off in la la land trying to get the car to run perfectly on bad plugs.
10-12-2002, 10:28 AM
#18
Suzuka Master
Originally posted by mattg
needing to reset the ecu is a myth.
but if you want to do it you don't need to leave the batt unhooked for hours on end. just disconnect the battery terminals and hold the + and - together for 15 seconds. then the ecu is reset.
i swear, some of the things i read on this site make me laugh.
needing to reset the ecu is a myth.
but if you want to do it you don't need to leave the batt unhooked for hours on end. just disconnect the battery terminals and hold the + and - together for 15 seconds. then the ecu is reset.
i swear, some of the things i read on this site make me laugh.
Funny, but within 10-minutes of driving with the newly installed header and CAI, the car was flying...
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