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| Forum name | Performance/Engine |
| Topic subject | wideband off the chart during deceleration |
| Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=131611 |
131611, wideband off the chart during deceleration Posted by rshissler, Sep-15-10 12:31 PM
Just turned my car back to stockish condition since the cams i had were messing with my ECU pretty bad and i didn't wanna send money on a piggyback. So today i just got everything bakc together and took her for a drive but the wideband is still reading off the chart when i leave off the gas in gear to slow down untill about 2k. Also have a random high idle that i cant track down. I changed the TPS and IAC sensor both did'nt do a thing to help. If i rev the car the idle will go back to normal most of the time.
Forgot to mention that its off the chart red, lean
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131612, RE: wideband off the chart during deceleration Posted by TurbchargdSpydr, Sep-15-10 01:58 PM
Some more information, what other mods did you have done to your car? is it completly stock or are there still aftermarket parts on it, ex: turbo, bigger injectors, ect...
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131613, RE: wideband off the chart during deceleration Posted by rshissler, Sep-15-10 02:19 PM
all thats on the car yet is UDP, 55mm TB, intake spacer, header/exhuast and Screaming Demon coil
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131614, RE: wideband off the chart during deceleration Posted by TurbchargdSpydr, Sep-15-10 03:19 PM
One guy says, "Check wiring/ground to TPS/IAC/CPS." Another says, "It always runs lean when you let off the throttle." Conclustion, "Could be a jacked fuel injector, clogged filter, or dying pump... But 99 times out of 100 it's an exhaust leak."...hope this helps
P.S - I sent you a PM about those gears...
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131615, RE: wideband off the chart during deceleration Posted by rshissler, Sep-15-10 05:38 PM
everyone on dsmtuners is tellin me its normal....
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131616, RE: wideband off the chart during deceleration Posted by TurbchargdSpydr, Sep-15-10 08:22 PM
alright so thats good news...so i guess your set...
Cam gears???lol
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131617, RE: wideband off the chart during deceleration Posted by bagged420a, Sep-15-10 09:39 PM
It goes lean because your are no longer on the gas pedal therfore the gas isn't going into the motor. Its normal for it to peg out when you let off the throttle
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131618, RE: wideband off the chart during deceleration Posted by rshissler, Sep-15-10 09:48 PM
alright thanks guys. it just had me freaked out since i've never seen one shoot off the chart like that before
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131622, RE: wideband off the chart during deceleration Posted by TurbchargdSpydr, Sep-16-10 08:45 AM
Originally posted by rshissler alright thanks guys. it just had me freaked out since i've never seen one shoot off the chart like that before
cam gears??
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131624, RE: wideband off the chart during deceleration Posted by DarkOne, Sep-16-10 02:13 PM
Originally posted by rshissler alright thanks guys. it just had me freaked out since i've never seen one shoot off the chart like that before
Blind leading the blind in this thread...
Yes, it's totally normal. The stock ECU completely cuts fuel on decel, i.e. the MAP sensor reads high vacuum and the TPS reads closed, the ECU cuts fuel, as you're engine braking.
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131629, RE: wideband off the chart during deceleration Posted by TurbchargdSpydr, Sep-16-10 03:52 PM
Originally posted by DarkOne Blind leading the blind in this thread...
what ever got the job done...lol
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131631, RE: wideband off the chart during deceleration Posted by 740 turbo brick, Sep-16-10 05:53 PM
Originally posted by DarkOneOriginally posted by rshissler alright thanks guys. it just had me freaked out since i've never seen one shoot off the chart like that before Blind leading the blind in this thread... Yes, it's totally normal. The stock ECU completely cuts fuel on decel, i.e. the MAP sensor reads high vacuum and the TPS reads closed, the ECU cuts fuel, as you're engine braking.
LOL.
Exactly right. This is where the debate of what saves more gas, neutral coasting or engine braking comes in. If you are completely off the gas in gear at any RPM above I think 1600 RPM, the ECU completely shuts off the fuel injectors to save fuel and aid in slowing down. This is even an option in Engine control systems like Megasquirt.
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131634, RE: wideband off the chart during deceleration Posted by Ebster1085, Sep-17-10 08:19 PM
One of the worst threads I have ever read...lock?
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