Ice on pipe from evaporator

[Charles5654]

When the A/C on my 2002 Civic SI is on, I can see ice forming on the surface of the pipe coming from the evaporator. This evaporator was installed less than one year ago, because the previous evaporator was leaking. The A/C has been working since then, but has never been strong, which, I thought, was due to the compressor being old. Now after seeing the ice on the pipe, I am less sure.
What procedure should be used to determine the reason of the ice formation?

Thanks

[Tim]

Could be low on refrigerant. Might consider reclaiming and checking refrigerant amount by weight.

[Charles5654]

Could be low on refrigerant. Might consider reclaiming and checking refrigerant amount by weight.

Thanks for reply. The refrigerant was checked and found ok. Any chances that the problem could be related to the evaporator temperature probe not working properly?

[Tim]

short answer, Yes.

[JohnHere]

Presuming the charge isn't low, If the evaporator temp sensor is out of spec, it could cause the evaporator core and suction line to ice-up by keeping the compressor on too long. Do you notice any reduced airflow from the vents and/or the blower changing its sound after running the system for 15 minutes or so?

[Charles5654]

Presuming the charge isn't low, If the evaporator temp sensor is out of spec, it could cause the evaporator core and suction line to ice-up by keeping the compressor on too long. Do you notice any reduced airflow from the vents and/or the blower changing its sound after running the system for 15 minutes or so?

I don't remember this happening last summer, but perhaps I was not paying close attention. I will be monitoring the airflow and changes in the sound of the blower now.
Thanks

[Charles5654]

Might also be a jammed open TXV. Especially if AC is wimpy all the time, not just ice cold for some time then gradually warmer (this is what an evaporator that is running too cold usually yields). Too much refrigerant flowing through, suction gets too high (so the evaporator can't get cold enough) and the refrigerant has to evaporate somewhere else than within the evaporator.

The TXV was changed when the evaporator was changed. Both were good quality, aftermarket.
I will have the TXV checked.
Thanks