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View Full Version : is ecu switching maps when check engine is on?



maikcat
10-03-2011, 04:13 AM
hello all,

i have check engine on due to the fact i replaced dp (catless).

my question is:

is the ecu switches to low octane fuel map or the check engine doesnt affect it?

Thank you in advance

Michael.

Dubs46
10-03-2011, 07:49 AM
It won't affect it, all you need is a spark plug non fouler or have your tuner disable your rear o2. That will turn off your CEL code.

Alfred@TTech
10-04-2011, 10:03 AM
hello all,

i have check engine on due to the fact i replaced dp (catless).

my question is:

is the ecu switches to low octane fuel map or the check engine doesnt affect it?

Thank you in advance

Michael.


Dubs is correct in regards to the possible fixes. The only time that the ECU begins to reference the low octane fuel and ignition maps is when enough knock at WOT has been present to decrease the octane flag number. If you have not had your ECU remapped for your modifications, like Dubs said, you can have the tuner flash that cel out at the time of tuning.

Good luck and if you need more help feel free to pm me.Â* :mitsu:

Alfred

Dubs46
10-04-2011, 10:10 AM
Alfred to the rescue Lol

render
03-31-2012, 05:35 PM
Wait doesn't that CEL (no rear 02 fouler) affect the closed loop delta thus possibly pushing the ECU into low octane fuel map on quick throttle transition? Am I getting my cars confused?

Black Evo Beauty
04-02-2012, 10:37 AM
hello all,

i have check engine on due to the fact i replaced dp (catless).

my question is:

is the ecu switches to low octane fuel map or the check engine doesnt affect it?

Thank you in advance

Michael.


Dubs is correct in regards to the possible fixes. The only time that the ECU begins to reference the low octane fuel and ignition maps is when enough knock at WOT has been present to decrease the octane flag number. If you have not had your ECU remapped for your modifications, like Dubs said, you can have the tuner flash that cel out at the time of tuning.

Good luck and if you need more help feel free to pm me.Â* :mitsu:

Alfred
^^^^^^ listen to the man

render
04-02-2012, 11:48 AM
Except as I recall (haven't tuned an evo in a long time) is that #1 there is a very limited range of knock detection at WOT and #2 both WOT and partial throttle can result in low octane fuel maps. This is incorrect?

amaev05
04-03-2012, 04:29 PM
there have been may advancements in the tuning of the stock ecu. the knock tables can be set as desired by the tuner by rpm and ignore a designated load value, and also sensitivity of the knock sensor, as well as a flashing cel when a designated knock value has been detected.
and yes when the ecu detects a certin amount of knock it will begin to pull timing, then calculates the knock and will eventually begin to interpolate the low octane map

but im not sure what this has to do with a rear o2 sensor cel.