04em2civic

So I just bought an 04 em2. It has 130k on it. When I bought it 2 weeks ago I found out it needed a head gasket. Just got that done yesterday and picked the car up today. Ran great then when I hit vtec a couple times a check engine light came on for p2646. Shop can't figure out anything with it. Looked into it and found most likely cause to be fault pressure switch. I have one coming. I did the test of checking for continuity at 3000rpm with the sensor unhooked and found continuity at 3000. From what I read that means faulty pressure switch. Is there any other way to narrow this down? We just did an oil change on the car because of the bad head gasket. Oil level is fine. Vtec engages fine for a couple tries then does this. I should also state that on the shops scan tool with the car running it says the switch is on. If you drive the car the switch stays on and when vtec engages the solenoid opens. If I read correctly the switch isn't suppose to stay on all the time correct?

NDNV

If it is not the VTEC switch itself maybe the screen needs to be cleaned.

04em2civic

Replaced the switch and it hasn't been on yet. Where is the filter located on an em2?

NDNV

I would think the filter is part of the VTEC switch. Did you notice a filter screen on the new part you replaced?