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Old 05-12-2005, 07:21 AM
PuntoRex PuntoRex is offline
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Join Date: Mar 2004
Location: Taiwan
Posts: 75
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Be cautious about triming the MAF signal.

Some ECU might 'work around' the changed signal & keep the a/f constant by the O2 sensor feedback. I suspect, it does so even in open loop mode...

I've tried triming the MAF signal by more than 20% of the voltage, but the ECU eventually adapted to it & kept the engine running in the original condition. All I've done to the MAF signal seems in vain.

Later I tried to trim the O2 sensor signal, by very small steps, then it worked. So I guess in this case, the O2 sensor signal is in a higher priority than the MAF in fueling control. Interceptor has its own limitation in such cases.

This was my own experience with Bosch Motronic ECU. It might be varied a lot in different cars. For your reference.
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