Hi All

I have been using the PLX M300 with the mods as in the forum and it worked great for over two years. My device finally failed and i cant purchase the same anymore so i had to go with the newer SM AFR without a screen attached to it.

I got a TTL RS232 adapter which I had for the previous PLX and did the same mods +3.3, GND and TX to the adapter VCC, GND and TX.

Selected wideband com port and PLX and now the readings are 280-290 AFR. I checked with PLX and they say nothing is changed. Can someone help me with what can be wrong ?

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I have attached the ground pin from the main power adapter. I have checked the TTL adapter and the power supply is 3.3 Volts. But the readings are way too high. I was happy using the old unit and really got used to it. I can't go back to an analog configuration now since i really liked the clean serial data.