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Old 09-09-2004, 02:27 PM
nitr0gen nitr0gen is offline
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Re: Re: 1994 escort 1.9L

Quote:
Originally Posted by jeffescortlx
Do what he said^

But, it also sounds like the O2 sensor is slow and shot. It run's normal when cold because the computer is on "open loop mode" to give time for the O2 to warm up to operating temp. Once warm the PCM switches to "closed loop" and trims the AFR off of what the O2 sensor is reading, a shot O2 sensor will read lean so the PCM thinks it needs to add a bunch of fuel when it does'nt, so you run over rich and that kill's your power.

The CEL does not always come on right away, the PCM needs to determain between a good O2 with a lean condition, or a bad O2 with a normal condition.
I forgot to mention that the O2 sensor has been swapped with a known working one. Sorry.
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