Hi, so two days ago I installed my knock sensor. To fit my hand through there I removed the 10mm nut under the EGRC valve bracket to move it out the way. I got my knock sensor in and everything was great. Tried tightening the EGRC with my 10mm wrench and it wouldn't go back on. So I just finger tightened it. A bit loose but nothing that made it move if that makes sense. Anyways I got a P1400 code today and I'm just wondering, because I didn't tighten my EGRC nut can that be throwing the code? Can I have bad grounding or power connection because it's not on the bracket tight? This is the EGRC btw. lol

I don't know the answer to your question, although it would surprise me if the loose nut caused the code. But a flex-head wrench or crows foot wrench will tighten it up nicely. I found a crows foot at Sears for about $3 a while back.

I lost the nut down in the engine bay about 3 years ago when I replaced my solenoid. It's just been hanging by the bolt since then. I've had no problems.

I wish I could remember what else I checked back then. Have you looked at the FSM?

Just an update. Turns out my EGRC Valve was not working. I replaced it, cleared check engine light with OBD2 Scanner, and I drove for 300 miles. Not one Check Engine Light Issue!